media: coda: add SPS fixup code for frame sizes that are not multiples of 16

The CODA7541 firmware does not set the SPS frame cropping fields to
properly describe coded h.264 streams with frame sizes that are not a
multiple of the macroblock size.
This adds RBSP parsing code and a SPS fixup routine to manually replace
the cropping information in the headers produced by the firmware with
the correct values.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
[hans.verkuil@cisco.com: added explanation of SPS RBSP to comment]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>