ALSA: hda - Consolidate cap_sync_hook and capture_switch_hook

Two hooks in hda_gen_spec, cap_sync_hook and capture_switch_hook, play
very similar roles.  The only differences are that the former is
called more often (e.g. at init or switching capsrc) while the latter
can take an on/off argument.

As a more generic implementation, consolidate these two hooks, and
pass snd_ctl_elem_value pointer as the second argument.  If the
secondary argument is non-NULL, it can take the on/off value, so the
caller handles it like the former capture_switch_hook.  If it's NULL,
it's called in the init or capsrc switch case.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 71a8894..70b0e32 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -670,7 +670,8 @@
 	}
 }
 
-static void alc_inv_dmic_hook(struct hda_codec *codec)
+static void alc_inv_dmic_hook(struct hda_codec *codec,
+			     struct snd_ctl_elem_value *ucontrol)
 {
 	alc_inv_dmic_sync(codec, false);
 }