media: cedrus: Remove unnecessary parenthesis around DIV_ROUND_UP

DIV_ROUND_UP's first argument doesn't need to be wrapped in parenthesis
since that is already being taken care of in the macro's definition.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>