[ARM] 4461/1: MXC platform and i.MX31ADS core support

This patch adds the foundation pieces for
the Freescale MXC platforms, including
i.MX2 and i.MX3 based systems.

The bare-bones MX31 support in this patch
boots to the rootdev panic with 8250 serial
console configured "console=ttyS0,115200".
It assumes that Redboot is the boot loader.

Signed-off-by: Quinn Jensen <quinn.jensen@freescale.com>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>