ARM: samsung: register syscore_ops for timer resume directly

Instead of using struct sys_timer's resume function, register syscore_ops
directly in s3c2410_timer_init(). This will allow the sys_timer suspend/
resume fields to be removed, and eventually lead to a complete removal of
struct sys_timer.

Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>