drm/exynos: mixer: enable video overlay plane only when VP is available

Video overlay plane should be registered only when suitable hardware
sub-block (Video Processor) is available.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
1 file changed