misc: mic: MIC VOP Bus

The Virtio Over PCIe (VOP) bus abstracts the low level hardware
details like interrupts and mapping remote memory so that the same VOP
driver can work without changes with different MIC host or card
drivers as long as the hardware bus operations are implemented. The
VOP driver registers itself on the VOP bus. The base PCIe drivers
implement the bus ops and register VOP devices on the bus, resulting
in the VOP driver being probed with the VOP devices. This allows the
VOP functionality to be shared between multiple generations of Intel
MIC products.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>