media: dvb-bt8xx: Make variable dst_config constant

Static structure dst_config, of type dst_config, is not used except to
be assigned as the value of field state of a variable having type
dst_state *. In the definition of dst_state, field config is declared as
const. Hence dst_config, when assigned to config, cannot be modified.
Therefore, make dst_config const as well.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/pci/bt8xx/dvb-bt8xx.c

@@ -393,7 +393,7 @@ static struct mt352_config advbt771_samsung_tdtc9251dh0_config = {
 	.demod_init = advbt771_samsung_tdtc9251dh0_demod_init,
 };
 
-static struct dst_config dst_config = {
+static const struct dst_config dst_config = {
 	.demod_address = 0x55,
 };