ALSA: fm801: implement TEA575x tuner autodetection

Autodetect TEA575x tuner connection type during init. This allows tuner to
work out-of-the box.

tea575x_tuner module parameter remains functional to force tuner type.

Tested with SF256-PCP and SF64-PCR.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>