[ARM] 4744/1: pcm027: add support for phyCORE-PXA270 CPU module

[ARM] 4744/1: pcm027: add support for phyCORE-PXA270 CPU module

This patch adds main support for the generic phyCORE-PXA270 CPU module
(aka PCM-027). Its as generic as possible to support any kind of baseboard.

Note: Neither the CPU module nor the pcm027.c implementation can work without
a baseboard support. Baseboard support can be added by the PCM-990 or any
custom variant.

V2:
 After comments by Eric Miao:
  - Currently unsupported devices moved into separate patch
  - direct call of baseboard initialisation

V3:
 After comments by Russell King
  - sort include files
  - setting RTC bit for power control removed
 - style problems fixed (discovered by checkpatch.pl)

Signed-off-by: Juergen Beisert <j.beisert@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>