[media] coda: round up internal frames to multiples of macroblock size for h.264

CODA7541 only supports encoding h.264 frames with width and height that are
multiples of the macroblock size.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>