ARM: S5P6450: Define base addresses for I2S

Define the base address of I2S-1 and 2 for S5P6450.

Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[kgene.kim@samsung.com: Added description]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>