[ALSA] Add missing dB scale information to vxpocket driver

Added the missing dB scale information for Mic volume
to vxpocket driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/pcmcia/vx/vxp_mixer.c b/sound/pcmcia/vx/vxp_mixer.c
index e237f6c..bced7b6 100644
--- a/sound/pcmcia/vx/vxp_mixer.c
+++ b/sound/pcmcia/vx/vxp_mixer.c
@@ -23,6 +23,7 @@
 #include <sound/driver.h>
 #include <sound/core.h>
 #include <sound/control.h>
+#include <sound/tlv.h>
 #include "vxpocket.h"
 
 #define MIC_LEVEL_MIN	0
@@ -63,12 +64,17 @@
 	return 0;
 }
 
+static DECLARE_TLV_DB_SCALE(db_scale_mic, -21, 3, 0);
+
 static struct snd_kcontrol_new vx_control_mic_level = {
 	.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access =	(SNDRV_CTL_ELEM_ACCESS_READWRITE |
+			 SNDRV_CTL_ELEM_ACCESS_TLV_READ),
 	.name =		"Mic Capture Volume",
 	.info =		vx_mic_level_info,
 	.get =		vx_mic_level_get,
 	.put =		vx_mic_level_put,
+	.tlv = { .p = db_scale_mic },
 };
 
 /*