[media] v4l: ti-vpe: Add a type specifier to describe vpdma data format type

The struct vpdma_data_format holds the color format depth and the data_type
value needed to be programmed in the data descriptors. However, it doesn't
tell what type of color format is it, i.e, whether it is RGB, YUV or Misc.

This information is needed when by vpdma library when forming descriptors. We
modify the depth parameter for the chroma portion of the NV12 format. For this,
we check if the data_type value is C420. This isn't sufficient as there are
many YUV and RGB vpdma formats which have the same data_type value. Hence, we
need to hold the type of the color format for the above case, and possibly more
cases in the future.

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>