ARM: SAMSUNG: Convert irq-vic-timer to irq_ functions

Conver the VIC timer interrupts to use the irq_ versions of the IRQ
operatiosn introduced in 2.6.37, storing the mask for the timer
interrupt in the chip_data of the irq_data in order to save having to
do a substraction and a shift on every operation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>