Create amdgpu_bo_handle from a GEM handle
This adds a new public drm api for amdgpu interface that returns an amdgpu_bo_handle from a GEM handle returned by the kernel mode driver. In certain situations, where the BO was allocated by non libdrm alloc API i.e. outside of amdgpu_bo_alloc (AMD ROCt APIs) then many libdrm apis can't be accessed as they depend on amdgpu_bo_handle which is created privately in response to amdgpu_bo_alloc. This allows other consumers of libdrm to benefit even if they didn't create the BO using libdrm. Typical consumers of this API will be amdgpu plugin to support checkpoint and restore (CRIU) of ROCm applications. https://github.com/RadeonOpenCompute/criu