ALSA: hda - Fix the wrong pin-cap check in patch_realtek.c

The check for the amp-output must be done for widget-caps rather than
pin-caps as implemented in the recent change...  Simply a thinko.

Also, add the similar checks to all places that put output-amp mutes
in the initialization.

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