media: camss: Replace hard coded value with parameter

Kernel test robot reported below warning ->
drivers/media/platform/qcom/camss/camss-csid-gen2.c:407:3:
warning: Value stored to 'val' is never read
[clang-analyzer-deadcode.DeadStores]

Replace hard coded value with val.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@gmail.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>