stm32: timers: fix mixup between TIMx_CCMR1 and TIMx_CCMR2 in timer_set_oc_mode()
stm32f3: drop redundant gpio.c

All methods in this file are in either
* common/gpio_common_all.c
* common/gpio_common_f0234.c

Those other files have better doxygen commentary, this file should never
have been added.
tiva lm4f: ssi: Initial implementation for SSI peripheral
docs: fix link from stm32f3 to stm32f0

Incorrectly pointed to f1.
Makefile: fix build for directories with spaces

When full path of a source directory has spaces in it, that makes
shell and Make split the path, so special treatment is
necessary. Additionally, @F doesn't honour the escaping, so has to be
avoided.

Reported-by: Roman Faizullin <roman@faizullin.info>
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
stm32: exti: Define all irqs in common header.

There's more exti lines on many more devices now. F0 and F3 have extras, as did
L1 and L0.  There's no real reason not to have higher order EXTI definitions
defined at the top level, and it reduces the number of files to merge together
to find all definitions for the bigger devices.

Signed-off-by: Karl Palsson <karlp@tweak.net.au>

Fixes #338
stm32/spi: Replace all SPIx_I2S_BASE with SPIx_BASE

Latest versions of all reference manuals refer to the address as SPIx_BASE, and
simply name some of the individual registers as SPI_I2SXXXX.  Likewise, the
interrupts are simply SPIx, not SPIx/I2Sx.  Rather than hacking more duplicates
into the F0 and L0 parts where this was turning up, remove the pointless _I2S_
from SPI2/SPI3 and make it all consistent

Compile tested only, with the examples collection.

Signed-off-by: Karl Palsson <karlp@tweak.net.au>

Fixes #331
Fixes #347
stm32: Add timers 9-17.  This should support all F0, F1, and F2 products
stm32: i2c: actually keep bit 14 set as per datasheet.

Old code did three writes, new way actually seems to follow datasheet
properly.
init: call pre_main before C++ constructors

This moves the platform specific initialization function pre_main
in front of C++ constructors. This is especially necessary for
platforms which need to setup the stack pointer (pre_main itself
is inline, hence no stack needed for this function).
stm32: gpio_toggle: ensure correct state of non-toggled pins.
Remove duplicate definitions for the DWT in SCS as we have specialized cm3/dwt.h for the DWT module already
Removed duplicate definitions for systick, we have module cm3/systick.h already.