[ARM] 3375/1: S3C2440 - fix osiris machine build

Patch from Ben Dooks

Fix the build of arch/arm/mach-s3c2410/mach-osiris.c
and fix the warnings from sparse.

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