qemu:virtio-net: Add promiscuous and all-multicast mode bits (Alex Williamson)

qemu:virtio-net: Add promiscuous and all-multicast mode bits (Alex Williamson)

Add a new RX_MODE control virtqueue class with commands PROMISC and
ALLMULTI and usage documented in virtio-net.h allowing the guest to
manipulate packet receiving options.  We don't export a feature for
this until we also add the MAC filter table.

Note, for compatibility with older guest drivers we need to default
to promiscuous.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6537 c046a42c-6fe2-441c-8c8c-71466251a162