Adds RemoteFX support to the Hyper-V driver

Blueprint: hyper-v-remotefx

Microsoft RemoteFX enhances the visual experience in RDP connections,
including providing access to virtualized instances of a physical GPU to
multiple guests running on Hyper-V.

In order to use RemoteFX in Hyper-V 2012, one or more DirectX 11 capable
display adapters must be present and the RDS-Virtualization server feature
must be installed.

This patch enables RemoteFX on Hyper-V Server / Windows Server 2012 and
above.

DocImpact
Change-Id: I91fabd5bce2564d48957e8aec1e50ff2625e5747