drm/i915/gvt: vGPU HW resource management

This patch introduces the GVT-g vGPU HW resource management. Under
GVT-g virtualizaion environment, each vGPU requires portions HW
resources, including aperture, hidden GM space, and fence registers.

When creating a vGPU, GVT-g will request these HW resources from host,
and return them to host after a vGPU is destroyed.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>