V4L/DVB (5716): Tda10086,tda826x: fix tuning, STR/SNR values

Several people reported unreliable reception with the current driver.
Furthermore, STR and SNR values seem to be inverted.
This fix is based on a patch posted by Hartmut Hackman.
Thanks to Helmut Auer for testing and helping to optimize the patch.
tda826x:
- set baseband cut-off to 19 MHz
tda10086:
- change the parameters of the carrier recovery loop
- toggle register 0x02 between 0x35 (tuning) and 0x00 (locked)
- invert STR and SNR values

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/tda826x.c b/drivers/media/dvb/frontends/tda826x.c
index 79f971d..bd3ebc2 100644
--- a/drivers/media/dvb/frontends/tda826x.c
+++ b/drivers/media/dvb/frontends/tda826x.c
@@ -89,8 +89,8 @@
 	buf[2] = (1<<5) | 0x0b; // 1Mhz + 0.45 VCO
 	buf[3] = div >> 7;
 	buf[4] = div << 1;
-	buf[5] = 0xff; // basedband filter to max
-	buf[6] = 0xfe; // gains at max + no RF attenuation
+	buf[5] = 0x77; // baseband cut-off 19 MHz
+	buf[6] = 0xfe; // baseband gain 9 db + no RF attenuation
 	buf[7] = 0x83; // charge pumps at high, tests off
 	buf[8] = 0x80; // recommended value 4 for AMPVCO + disable ports.
 	buf[9] = 0x1a; // normal caltime + recommended values for SELTH + SELVTL