vibrator: add initial forcefeedback vibrator HAL

This HAL talks to vibrators which are exposed as input devices using the
forcefeedback API.

This version includes lots of debugging spam.
diff --git a/manifest.xml b/manifest.xml
index 7ae10c3..b224933 100644
--- a/manifest.xml
+++ b/manifest.xml
@@ -115,4 +115,13 @@
             <instance>default</instance>
         </interface>
     </hal>
+     <hal format="hidl">
+        <name>android.hardware.vibrator</name>
+        <transport>hwbinder</transport>
+        <version>1.1</version>
+        <interface>
+            <name>IVibrator</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
 </manifest>