[media] Add Y10B, a 10 bpp bit-packed greyscale format

Add a 10 bits per pixel greyscale format in a bit-packed array representation,
naming it Y10B. Such pixel format is supplied for instance by the Kinect
sensor device.

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>