V4L/DVB (4606): Add driver for TUA6100

This driver was originally in budget-av.c, however I have extracted it into
a seperate file to permit reuse.
I also reworked the code to make it maintainable. I then examined the KNC1
windows drivers and rewrote the code in order to configure the PLL as they
do. This solves a lot of reported tuning problems.

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/Makefile b/drivers/media/dvb/frontends/Makefile
index 0b43942..dce9cf0 100644
--- a/drivers/media/dvb/frontends/Makefile
+++ b/drivers/media/dvb/frontends/Makefile
@@ -36,3 +36,4 @@
 obj-$(CONFIG_DVB_TDA10086) += tda10086.o
 obj-$(CONFIG_DVB_TDA826X) += tda826x.o
 obj-$(CONFIG_DVB_TUNER_MT2060) += mt2060.o
+obj-$(CONFIG_DVB_TUA6100) += tua6100.o