[media] media/i2c/Kconfig: drop superfluous MEDIA_CONTROLLER

These drivers depend on VIDEO_V4L2_SUBDEV_API, which in turn
depends on MEDIA_CONTROLLER. So it is sufficient to just depend
on VIDEO_V4L2_SUBDEV_API.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>