ALSA: hda - Fix initial capture source connections of ALC880/260

The widget connections of ADC of ALC880 and ALC2260 aren't initialized,
thus it might point to invalid pin.  This can be a problem when mode=auto
and there is only one input pin.  Then user can't change the connection
at all.

This patch adds the code to initialize the input pin connection of these
codecs.

Reference: Novell bnc#594363
	https://bugzilla.novell.com/show_bug.cgi?id=594363



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