add two arm mach-virt patches from pmaydell's linaro qemu tree

see https://bugs.launchpad.net/aberdeen/+bug/1234837

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
add entry to changelog

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
add 4 more mach-virt patches

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>