media: ipu3-imgu: Fixed some coding style issues in ipu3-css.c

Improved readability by fixing some issues related to maximum line length.

Signed-off-by: Felix Winkler <fxmw.tnt@gmail.com>
Signed-off-by: Niklas Witzel <nik.witzel@horsepower-hannover.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>