drm/amdgpu: add support of gfx10 register dump

Adding gfx10 gc registers to be used for register
dump via devcoredump during a gpu reset.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>