init: Add support for /dev/bus/usb/ file system and add new unix group AID_USB.

init now creates files in /dev/bus/usb/ for user access to USB devices.
Files are chmod 660 with group AID_USB.

Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index 46f640f..7845eb9 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -69,6 +69,7 @@
 /dev/qmi0                 0640   radio      radio
 /dev/qmi1                 0640   radio      radio
 /dev/qmi2                 0640   radio      radio
+/dev/bus/usb/*            0660   root       usb
 
 # CDMA radio interface MUX
 /dev/ts0710mux*           0640   radio      radio