[ARM] 2873/1: PCMCIA soc: Allow access to filesystems on CF at boot time

Patch from Richard Purdie

This change makes the soc pcmcia interfaces available earlier in the
boot process meaning devices like CF microdrives can be used for the
root filesystem.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>