[ARM] 5453/1: fix building breakage of sys_oabi-compat.c due to missing kmalloc/kfree

It seems that declarations of kmalloc/kfree are missed, explicitly
include it.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>