media: coda: allocate space for mpeg4 decoder mvcol buffer

The MPEG-4 decoder mvcol buffer was registered, but its size not added
to a frame buffer allocation. This could cause the decoder to write past
the end of the allocated buffer for large frame sizes.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>