Clean up and fix pwr_nids for 92HD71 / 73 / 83 family codecs; remove
pwr_mapping which was incorrect.

The original pwr_nids support of 92HD83xxx was incorrect and never
actually worked before.  Now we should have things working correctly
without having to hack by DID anymore.

It is also not necessary to explicitly turn on all the pins near the
beginning of patch_stac92hd83xxx() now, the pins will go though
initialization properly.

Tested on 92HD66 / 71 / 73 / 75 / 83 / 89 / 91 demo boards.
Signed-off-by: Charles Chin <Charles.Chin@idt.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>