uio-hv-generic: new userspace i/o driver for VMBus

uio-hv-generic: new userspace i/o driver for VMBus

Orabug: 26668113

This is a new driver to enable userspace networking on VMBus.
It is based largely on the similar driver that already exists
for PCI, and earlier work done by Brocade to support DPDK.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 95096f2fbd10186d3e78a328b327afc71428f65f)
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>