[media] soc-camera: fix static build of the sh_mobile_csi2.c driver

The test for driver->owner != NULL in sh_mobile_ceu_camera.c is unneeded and it
breaks the static build of sh_mobile_csi2.c. Remove it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>