ARM: S5PV210: Add s5pv210_sw_reset for SWRESET

This patch adds s5pv210_sw_reset() which includes SWRESET for S5PV210/S5PC110.

Signed-off-by: Jongpill Lee <boyko.lee@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>