[media] si2168: define symbol rate limits

w_scan complains about missing symbol rate limits:
This dvb driver is *buggy*: the symbol rate limits are undefined - please report to linuxtv.org

Chip supports 1 to 7.2 MSymbol/s on DVB-C.

Cc: stable@vger.kernel.org
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/si2168.c

@@ -635,6 +635,8 @@ static const struct dvb_frontend_ops si2168_ops = {
 	.delsys = {SYS_DVBT, SYS_DVBT2, SYS_DVBC_ANNEX_A},
 	.info = {
 		.name = "Silicon Labs Si2168",
+		.symbol_rate_min = 1000000,
+		.symbol_rate_max = 7200000,
 		.caps =	FE_CAN_FEC_1_2 |
 			FE_CAN_FEC_2_3 |
 			FE_CAN_FEC_3_4 |