ARM: SAMSUNG: Moving ADC device definition to plat-samsung.

This patch moves ADC device definition to plat-samsung.
Because that is generic to the S3C64XX and S5P Series SoCs.

Signed-off-by: Naveen Krishna Ch <ch.naveen@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>