mx28evk: extend default environment

The environment has been based on mx53loco and m28evk but keeping the
possibility to easy change the default console device as Freescale and
mainline kernels differ on the device name.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Cc: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
imx: Use a clear identification of an unidentified CPU type

In case an unidentified CPU type is detected it now returns
i.MX??, in a const char.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Cc: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>

Changes for v2:
 * use i.MX?? for unidentified CPU type
mx53loco: Add a comment about local print_cpuinfo method in board file

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Cc: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
mxs: generalize code for print_cpuinfo()

The information now is gathered from HW_DIGCTL_CHIPID register and
includes the revision of the chip on the output.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Cc: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>

Changes for v3:
 * fix info order (first rev, then clock)

Changes for v2:
 * use ?? for unidentified revision and cpu type
 * use numeric revisions
i.MX28: power: Check if we are using a valid VBUS

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
i.MX233: power: Add comment about registers with same offsets

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
i.MX233: add iomux-mx23.h

This has been copied from Linux source at revision 786f02b719f.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mxs: reorganize source directory for easy sharing of code in i.MXS SoCs

Most code can be shared between i.MX23 and i.MX28 as both are from
i.MXS family; this source directory structure makes easy to share code
among them.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mxs: prefix register acessor macros with 'mxs' prefix

As the register accessing mode is the same for all i.MXS SoCs we ought
to use 'mxs' prefix intead of 'mx28'.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mxs: prefix register structs with 'mxs' prefix

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mxs: SPL: use 'mxs' prefix for methods as it is mostly generic code

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
i.MX233: SPL: Disable i.MX28 specific power code

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
i.MX28: rename regs-clkctrl.h to regs-clkctrl-mx28.h

The CLKCTRL registers are SoC specific so we ought to have it clear on
filename.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mxsboot: stop referring to i.MX28 as this ought to work for all i.MXS SoCs

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mx23evk: add board information

This adds the i.MX23EVK board to be build. This board has:

 Processor: Freescale i.MX233

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
wip