media: i2c: gc2145: Galaxy Core GC2145 sensor support

Addition of support for the Galaxy Core GC2145 XVGA sensor.
The sensor supports both DVP and CSI-2 interfaces however for
the time being only CSI-2 is implemented.

Configurations are currently based on initialization scripts
coming from Galaxy Core and so for that purpose only 3 static
resolutions are supported:
 - 640x480
 - 1280x720
 - 1600x1200

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>