staging: media: rpivid: Select MEDIA_CONTROLLER and MEDIA_CONTROLLER_REQUEST_API

MEDIA_CONTROLLER_REQUEST_API is a hidden option. If rpivid depends on it,
the user would need to first enable another driver that selects
MEDIA_CONTROLLER_REQUEST_API, and only then rpivid would become available.

By selecting it instead of depending on it, it becomes possible to enable
rpivid without having to enable other potentially unnecessary drivers.

Signed-off-by: Hristo Venev <hristo@venev.name>