ARM: SAMSUNG: Convert irq-uart to use new irq_ functions

Convert to the new irq_ versions of the IRQ operations. As well as
the textual substituion of irq_data for the raw IRQ number we also
convert the register base lookup to in s3c_irq_uart_base() to pick
the irq_data up directly.

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