ALSA: hda - Resurrect input-source mixer of ALC268 model=acer

In the commit fdbc6626, I mistakenly
replaced the capture mixer array for ALC268_ACER to nosrc version
although this should be kept to alt_mixer.  Now fixed back.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_realtek.c

@@ -12660,7 +12660,7 @@ static struct alc_config_preset alc268_presets[] = {
 		.init_hook = alc268_toshiba_automute,
 	},
 	[ALC268_ACER] = {
-		.mixers = { alc268_acer_mixer, alc268_capture_nosrc_mixer,
+		.mixers = { alc268_acer_mixer, alc268_capture_alt_mixer,
 			    alc268_beep_mixer },
 		.init_verbs = { alc268_base_init_verbs, alc268_eapd_verbs,
 				alc268_acer_verbs },