[media] coda: fix internal framebuffer allocation size

This error was introduced by 5677e3b0
"[media] coda: update CODA7541 to firmware 1.4.50".

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>