AppArmor: Add access to /dev/mxc_vpu

Bosch reports access denied to /dev/mxc_vpu:

====
profile:/usr/lib/tracker/tracker-extract
apparmor:DENIED
denied_mask:wr
operation:open
name:/dev/mxc_vpu
requested_mask:wr

With kernel 3.14, Tracker needs access to /dev/mxc_vpu.

Signed-off-by: Frédéric Danis frederic.danis@collabora.com