asoc: qcs405: fix compilation issue

fix compilation issue due to missing forward declartion.

Change-Id: I64feb9e1baf25ad725f4333931726feceee2979a
Signed-off-by: Mangesh Kunchamwar <[email protected]>

asoc/qcs405.c

@@ -564,7 +564,8 @@ static struct msm_asoc_wcd93xx_codec msm_codec_fn;
 static int msm_snd_enable_codec_ext_clk(struct snd_soc_codec *codec,
 					int enable, bool dapm);
 static int msm_wsa881x_init(struct snd_soc_component *component);
-
+static int msm_snd_vad_cfg_put(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol);
 
 static struct snd_soc_dapm_route wcd_audio_paths[] = {
 	{"MIC BIAS1", NULL, "MCLK TX"},