[ALSA] hda-intel - Fix microphone capture with ALC880 F1734 model

The default capture source should be the mic which is 0x01 on this model.
In addition to that the change to VREF50 allows for higher capture volume.

Signed-off-by: Michael Gruber <lists.mg@googlemail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>