[PATCH] ARM: Fix Xscale copy_page implementation

The ARM copypage changes in 2.6.12-rc4-git1 removed the preempt locking
from the copypage functions which broke the XScale implementation.
This patch fixes the locking on XScale and removes the now unneeded
minicache code.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Checked-by: Richard Purdie