V4L/DVB (7654): tda10086: make the xtal frequency a configuration option

Some DVB-S boards, i.e. with the SD1878 tuner, use a 4 MHz reference frequency.
This reqires a different setup of the clock PLL.
This patch adds an enum to the tda10086_config struct and sets the proper
values for the boards.

This patch also fixes the DVB-S section of the MD7134_BRIDGE_2

Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/dvb-usb/ttusb2.c b/drivers/media/dvb/dvb-usb/ttusb2.c
index 706687c..20ca9d9 100644
--- a/drivers/media/dvb/dvb-usb/ttusb2.c
+++ b/drivers/media/dvb/dvb-usb/ttusb2.c
@@ -147,6 +147,7 @@
 	.demod_address = 0x0e,
 	.invert = 0,
 	.diseqc_tone = 1,
+	.xtal_freq = TDA10086_XTAL_16M,
 };
 
 static int ttusb2_frontend_attach(struct dvb_usb_adapter *adap)