[ARM] Move zone adjustment for SA1111 on SA11x0 platforms

Unfortunately, using PAGE_SHIFT in asm/arch/memory.h is unsafe, and we
can't include asm/page.h into this file because then we have a circular
dependency.  Move the offending code to arch/arm/common/sa1111.c
instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>