drm/amdgpu: add mmhub v3_0_2 ip headers

Add mmhub v3_0_2 register offset and shift masks

v2: update to latest headers

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>