[media] davinci: dm355: Fix uninitialized variable compiler warnings

drivers/media/platform/davinci/dm355_ccdc.c:593:9: warning: ‘val1’ may be
used uninitialized in this function [-Wuninitialized]
drivers/media/platform/davinci/dm355_ccdc.c:560:6: note: ‘val1’ was declared here
This is a false positive but the compiler has no way to know about it,
so initialize the variable to 0.

Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>