media: v4l: Add new 10-bit packed grayscale format

The new format will be called V4L2_PIX_FMT_Y10P.
It is similar to the V4L2_PIX_FMT_SBGGR10P family formats
but V4L2_PIX_FMT_Y10P is a grayscale format.

Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>