ALSA: hda - Fix initial capsrc selection in patch_alc269()

In patch_alc269(), we initialize the primary capsrc so that the device
works from the beginning.  It issues CONNECT_SEL verb no matter which
widget is although some widget (e.g. 0x23) has no connection selection
but a mixer, which requires unmuting instead.

This patch fixes the initialization of capsrc by re-using the code as
a helper function.

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