drm/amdgpu: Add navi10 kfd support for amdgpu (v3)

KFD (Kernel Fusion Driver) is the compute backend driver
for AMD GPUs.

v2: squash in updates (Alex)
v3: fix warnings (Alex)

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Signed-off-by: Philip Cox <Philip.Cox@amd.com>
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>