The workaround to force VREF50 for dallas/hp model with ALC861VD
was introduced in commit 8fdcb6fe4204bdb4c6991652717ab5063751414e,
but it contained wrong pincap override bits.
This patch fixes to exclude VREF80 pincap bit correctly.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>