[media] s5p-tv: Add PM_RUNTIME dependency

The TVOUT driver requires PM_RUNTIME support for proper clock
enabling.

Signed-off-by: Hatim Ali <hatim.rv@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>