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/ueventd.common.rc b/ueventd.common.rc
index b87dccf..bde2ad5 100644
--- a/ueventd.common.rc
+++ b/ueventd.common.rc
@@ -8,3 +8,6 @@
 
 # media.codec2
 /dev/ion 0664 system system
+
+# Input devices
+/dev/input/* 0660 system input