V4L/DVB (3371): Turn frame locked sound on, basic support for FM radio with TDA8275(a)

- Enabled audio PLL. This is mandatory for NICAM sound
- modify FM IF frequency to 5.5MHz for SAA7133/35 if tuner is tda8290

Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>