ALSA: hda - Use the new power control for VIA codecs

VIA codecs used to have the own power controls but they were disabled
at transition to the generic parser due to the coding assuming the
fixed routes.  Now we get the proper support of equivalently fine
power management in the generic parser, and the old kludges can be
replaced with it.  This results in the reduction of lots of dead
codes.

The advanced PM feature is disabled as default like before for keeping
the compatible behavior.  It's enabled via "Dynamic Power-Control"
mixer element.

Signed-off-by: Takashi Iwai <tiwai@suse.de>