drm/amdgpu/gfx10,11: use memcpy_to/fromio for MQDs

Since they were moved to VRAM, we need to use the IO
variants of memcpy.

Fixes: 1cfb4d61 ("drm/amdgpu: put MQDs in VRAM")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>