iMX28: Initial support for iMX28 CPU

This patch supports:
- Timers
- Debug UART
- Clock

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
19 files changed