ARM: S5P: HRT support

This patch adds support HR-Timer(High Resolution Timer) and dynamic
tick system for S5P SoCs. There are many clock sources for HR-Timer
on S5P SoCs. The PWM timer, RTC, System Timer, and MCT can be used
for clock source.
This patch can only support PWM timer for clock source of S5P64X0
and S5PV210.

Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>