ARM: S5P: add L2 early resume code

This patch adds code to resume L2 before MMU is enabled in
suspend and cpuidle resume paths. s3c_cpu_resume is moved to the
data section with appropriate comments.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>