[media] media drivers: annotate fall-through

Avoid warnings like those:

drivers/media/pci/ddbridge/ddbridge-core.c: In function 'dvb_input_detach':
drivers/media/pci/ddbridge/ddbridge-core.c:787:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (input->fe) {
      ^
drivers/media/pci/ddbridge/ddbridge-core.c:792:2: note: here
  case 4:
  ^~~~
...

On several cases, it is just that gcc 7.1 is not capable of
understanding the comment, but on other places, we need an
annotation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/dvb-frontends/s5h1411.c b/drivers/media/dvb-frontends/s5h1411.c
index f29750a..dd09336 100644
--- a/drivers/media/dvb-frontends/s5h1411.c
+++ b/drivers/media/dvb-frontends/s5h1411.c
@@ -51,7 +51,7 @@ static int debug;
 #define dprintk(arg...) do {	\
 	if (debug)		\
 		printk(arg);	\
-	} while (0)
+} while (0)
 
 /* Register values to initialise the demod, defaults to VSB */
 static struct init_tab {
@@ -410,7 +410,7 @@ static int s5h1411_set_if_freq(struct dvb_frontend *fe, int KHz)
 	default:
 		dprintk("%s(%d KHz) Invalid, defaulting to 5380\n",
 			__func__, KHz);
-		/* no break, need to continue */
+		/* fall through */
 	case 5380:
 	case 44000:
 		s5h1411_writereg(state, S5H1411_I2C_TOP_ADDR, 0x38, 0x1be4);