[PATCH] ARM: 2755/1: describe ixp2000 virtual memory map layout

Patch from Lennert Buytenhek

Add a comment to asm/arch-ixp2000/ixp2000-regs.h describing the
ixp2000 virtual memory map layout.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>