media: i2c: add lt6911uxe hdmi bridge driver

Lontium LT9611UXE is a HDMI to MIPI CSI-2 bridge. The device supports
modes up to 4k@60fps, obtains the video information and switches the
current mode once the video signal changes.

Signed-off-by: Dongcheng Yan <dongcheng.yan@intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
[hverkuil: fix smatch warning: missing error code 'ret']
[hverkuil: fix coccinelle IRQF_ONESHOT warning]