T108: fix adc test error

Change-Id: I8e38d6a27d378ce97d208847ad67247f28e0d040
diff --git a/mbtk/mbtk_lib/src/mbtk_adc.c b/mbtk/mbtk_lib/src/mbtk_adc.c
index 581bcba..fbe6a5c 100755
--- a/mbtk/mbtk_lib/src/mbtk_adc.c
+++ b/mbtk/mbtk_lib/src/mbtk_adc.c
@@ -64,7 +64,7 @@
     char *adc_value = NULL;
     char adc =(channle == MBTK_ADC0 ? '0' : (channle == MBTK_ADC1 ? '1' : '2'));
 
-#if (defined(MBTK_PROJECT_L508_X6) || defined(MBTK_PROJECT_T108))
+#if defined(MBTK_PROJECT_L508_X6)
     switch(channle)
     {
         case MBTK_ADC0:
@@ -102,6 +102,17 @@
             return -1;
         }
     }
+#elif defined(MBTK_PROJECT_T108)
+    if(!access(ADC_DEVICE_AUX, R_OK))
+    {
+        LOGI("[adc] DEV:%s", ADC_DEVICE_AUX);
+        fd = open(ADC_DEVICE_AUX, O_RDWR|O_CREAT|O_TRUNC, 0644);
+    }
+    else
+    {
+        LOGE("No found ADC devices.");
+        return -1;
+    }
 #else
     if(!access(ADC_DEVICE_802, R_OK)) {
         //LOGI("DEV:%s", ADC_DEVICE_802);