Mark qemu_device as a mlstrustedobject.

Allow apps running with any level to write to it.

Change-Id: I8fca1f377e14c624db5273bdacf8400addc6210d
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Merge "Mark qemu_device as a mlstrustedobject."
Merge remote-tracking branch 'upstream/master'