ALSA: parisc: Constify snd_kcontrol_new items

Most of snd_kcontrol_new definitions are read-only and passed as-is.
Let's declare them as const for further optimization.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-43-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/parisc/harmony.c

@@ -797,7 +797,7 @@ snd_harmony_captureroute_put(struct snd_kcontrol *kc,
   .private_value = ((left_shift) | ((right_shift) << 8) |            \
                    ((mask) << 16) | ((invert) << 24)) }
 
-static struct snd_kcontrol_new snd_harmony_controls[] = {
+static const struct snd_kcontrol_new snd_harmony_controls[] = {
 	HARMONY_VOLUME("Master Playback Volume", HARMONY_GAIN_LO_SHIFT, 
 		       HARMONY_GAIN_RO_SHIFT, HARMONY_GAIN_OUT, 1),
 	HARMONY_VOLUME("Capture Volume", HARMONY_GAIN_LI_SHIFT,