Revert "ALSA: hda - Use position_fix=3 as default for AMD chipsets"

This reverts commit 447ee6a7.

The workaround introduced by this commit seems bogus.
The AMD chipsets don't provide proper position-buffer nor FIFO value
required by VIACOMBO fix.

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