[ARM] 2975/1: S3C2410: time.c missing include of cpu.h

Patch from Ben Dooks

arch/arm/mach-s3c2410/time.c is missing include
of cpu.h, causing the declaration of the timer
struct (s3c24xx_timer) to be flagged as missing
the declaration.

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