Prevent framebuffer mmio space from being allocated to other devices on HyperV.

On Gen2 VMs, Hyper-V provides mmio space for framebuffer.
This mmio address range is not useable for other PCI devices.
Currently only efifb driver is using this range without reserving
it from system.
Therefore, vmbus driver reserves it before any other PCI device
drivers start to request mmio addresses.

PR: 222996
Submitted by: weh@microsoft.com
Reported by: dmitry_kuleshov@ukr.net
Reviewed by: decui@microsoft.com
Sponsored by: Microsoft