ARM: SAMSUNG: use spin_lock_irqsave() in clk_{enable,disable}

The clk_enable()and clk_disable() can be used process and ISR either.
And actually it is used for real product and other platforms use it
now. So spin_lock_irqsave() should be used instead.

Signed-off-by: Minho Ban <mhban@samsung.com>
Signed-off-by: Jaecheol Lee <jc.lee@samsung.com>
Signed-off-by: Sunyoung Kang <sy0816.kang@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>