ARM: S5PC1xx: add platform helpers for s3c-fb device

Samsung S5PC100 has LCD-controller compatible with the one known from
previous SoCs series. Add required platform setup and support code that
it can be used with s3c-fb driver.

Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>