p930: updates for 4.4

 * Update permissions for /firmware mount
 * Add mount for /modem
 * Update sdcard entry

Change-Id: I7a8d5bd6828297b7fb2fae9bcd8628ccb96bbace
Initial bringup for PACE

Change-Id: I4f1f4631cd5af85f00955ce5412f61358cc1b5ae