kvm tools, mips: Add MIPS support

So far this was tested with host running KVM using MIPS-VZ (on Cavium
Octeon3). A paravirtualized mips kernel was used for the guest.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>