media: i2c: lt6911uxe: add two selects to Kconfig

In order to get the v4l2_subdev functions you need to select
MEDIA_CONTROLLER and VIDEO_V4L2_SUBDEV_API.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503151002.HacBN2LO-lkp@intel.com/
Fixes: e49563c3 ("media: i2c: add lt6911uxe hdmi bridge driver")