vibrator intensity: disable tunable framework if not supported

Change-Id: I6481b82b7ee5412234d42e39f7f5560489f14af3
diff --git a/cmhw/org/cyanogenmod/hardware/VibratorHW.java b/cmhw/org/cyanogenmod/hardware/VibratorHW.java
index 970d74e..b6fa263 100755
--- a/cmhw/org/cyanogenmod/hardware/VibratorHW.java
+++ b/cmhw/org/cyanogenmod/hardware/VibratorHW.java
@@ -29,7 +29,13 @@
     private static String LEVEL_THRESHOLD_PATH = "/sys/class/timed_output/vibrator/pwm_threshold";
 
     public static boolean isSupported() {
-        return true;
+        File f = new File(LEVEL_PATH);
+
+        if(f.exists()) {
+            return true;
+        } else {
+            return false;
+        }
     }
 
     public static int getMaxIntensity()  {