[media] dvb_frontend: estimate bandwidth also for DVB-S/S2/Turbo

The needed bandwidth can be estimated using the symbol rate and
the rolloff factor. This could be useful for the frontend drivers,
as they don't need to calculate it themselves.
Reported-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/dvb-core/dvb_frontend.c

@@ -2072,6 +2072,23 @@ static int dtv_set_frontend(struct dvb_frontend *fe)
 	case SYS_DVBC_ANNEX_C:
 		rolloff = 113;
 		break;
+	case SYS_DVBS:
+	case SYS_TURBO:
+		rolloff = 135;
+		break;
+	case SYS_DVBS2:
+		switch (c->rolloff) {
+		case ROLLOFF_20:
+			rolloff = 120;
+			break;
+		case ROLLOFF_25:
+			rolloff = 125;
+			break;
+		default:
+		case ROLLOFF_35:
+			rolloff = 135;
+		}
+		break;
 	default:
 		break;
 	}