ARM: S3C64XX: Dynamically allocate the IRQ range for WM8994 on Cragganmore

Use the new irqdomain support in the WM8994 driver to dynamically allocate
the interrupt range for the WM8994 rather than doing it explicitly. This
is more idiomatic for modern interrupt usage.

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