cc2538: Clean up port and pin definitions

Homogenize port and pin definitions naming:
 - PERIPHERAL_FUNCTION_PORT for the port ID,
 - PERIPHERAL_FUNCTION_PIN for the pin ID,
 - PERIPHERAL_FUNCTION_PORT_BASE for the port base,
 - PERIPHERAL_FUNCTION_PIN_MASK for the pin mask.

Define only PERIPHERAL_FUNCTION_PORT and PERIPHERAL_FUNCTION_PIN in board.h, and
deduce PERIPHERAL_FUNCTION_PORT_BASE and PERIPHERAL_FUNCTION_PIN_MASK in the
driver from the former definitions.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
cc2538: usb: Make the GPIO driving the pull-up optional

The data sheet recommends that the USB pull-up resistor be driven by a GPIO so
that it can be controlled by software, but this is not mandatory. Hence, leave
the choice so that CC253-based boards not using this option can build and work
fine.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
cc2538: lpm: Give access to the SRAM non-retention area for PM2

If PM2 is enabled with LPM_CONF_MAX_PM, but not active, the non-retention area
of the SRAM can be useful to place temporary data that does not fit in the
low-leakage SRAM, typically after having called lpm_set_max_pm(LPM_PM1). Hence,
give access to this non-retention area thanks to .nrdata* sections.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
cc2538dk: Make it possible to override SLIP_ARCH_CONF_ENABLED

As the comment in contiki-conf.h says, the automatic definition of
SLIP_ARCH_CONF_ENABLED works only if UIP_FALLBACK_INTERFACE is tied to SLIP. If
UIP_FALLBACK_INTERFACE is set to another interface, SLIP_ARCH_CONF_ENABLED is
still automatically set to 1, leading to unwanted SLIP_END characters from
dbg.c:putchar() being printed on the UART.

This change makes it possible to force the definition of SLIP_ARCH_CONF_ENABLED
(e.g. from project-conf.h), so that it can be disabled if UIP_FALLBACK_INTERFACE
is used with something else than SLIP.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
cc2538: gpio: Add macros to use GPIO power-up interrupts

The GPIO power-up interrupts have to be configured and enabled in order to be
able to wake-up the SoC from PM1+ upon a signal edge occurring on a GPIO input
pin.

This set of macros allows to:
 - configure the signal edge triggering a power-up interrupt,
 - enable and disable a power-up interrupt,
 - clear a power-up interrupt flag.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
cc2538: gpio: Clear the power-up interrupts in the port ISRs

The pending GPIO power-up interrupts have to be cleared in the ISRs in order not
to re-trigger the interrupts and the wake-up events.

The power-up interrupts of all pins are cleared for each port in the
corresponding port ISR. This is done after calling the registered callbacks so
that the callbacks can know which pin woke up the SoC. This is done after
clearing the regular interrupt in order to avoid getting a new wake-up interrupt
without the regular interrupt in the case of a new wake-up edge occurring
between the two clears.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Removed the xmac.c code
Removed the lpp.c code
Don't compile webserver-ipv6 for the sky platform, as it is a little too small. Use the larger exp5438 instead
Remove Sensinode tests from travis
Merge pull request #42 from g-oikonomou/remove-sensinode-tests

Remove Sensinode tests from travis
Avoid access to the address register during auto-increment.

It cannot be ruled out that access to the address register triggers
an address auto-increment. Therefore a temporary address register
shadow is introduced to replace the access to the address regsiter.

Additionally there are several minor beautifications.
Merge pull request #488 from oliverschmidt/master

Avoid access to the address register during auto-increment.
Merge remote-tracking branch 'upstream/master'
Merge pull request #484 from adamdunkels/push/travis-fix

Partial fix for travis
Merge pull request #479 from adamdunkels/push/cleanup-xmac-and-lpp

Remove xmac.c and lpp.c
Merge pull request #466 from ADVANSEE/cc2538dk-slip-enable

cc2538dk: Make it possible to override SLIP_ARCH_CONF_ENABLED
Merge pull request #464 from ADVANSEE/cc2538-pm2-sram

cc2538: lpm: Give access to the SRAM non-retention area for PM2
Merge pull request #471 from ADVANSEE/cc2538-gpio-power-up

cc2538: gpio: Add support for power up
cc2538dk: startup-gcc: Do not redefine SYS_CTRL_EMUOVR

SYS_CTRL_EMUOVR is already defined in sys-ctrl.h, so #include this header file
instead of redefining SYS_CTRL_EMUOVR in startup-gcc.c.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>