media: i2c: Add the ov7740 image sensor driver

The ov7740 (color) image sensor is a high performance VGA CMOS
image snesor, which supports for output formats: RAW RGB and YUV
and image sizes: VGA, and QVGA, CIF and any size smaller.

Signed-off-by: Songjun Wu <songjun.wu@microchip.com>
Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>