The ov2640 has the test pattern generator features.  This makes use of
it through V4L2_CID_TEST_PATTERN control.

[Sakari Ailus: Use "Eight Vertical Colour Bars" as the second manu entry]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>