media: i2c: Add GC05A2 image sensor driver

Add a V4L2 sub-device driver for Galaxycore GC05A2 image sensor.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Zhi Mao <zhi.mao@mediatek.com>
[Sakari Ailus: Fold in MAINTAINERS change.]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>