drm/exynos: fimd: Add support for S5PV210 FIMD variant

This patch adds support for FIMD variant found on S5PV210 SoC.
Except CLKSEL bit availability, it is identical to Exynos4210.

Tested-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>