Revert "drm/amdgpu/gfx9: fix the doorbell missing when in CGPG issue."

Revert "drm/amdgpu/gfx9: fix the doorbell missing when in CGPG issue."

commit ee5468b9f1d3bf48082eed351dace14598e8ca39 upstream.

This reverts commit 4cbbe34807938e6e494e535a68d5ff64edac3f20.

Reason for revert: side effect of enlarging CP_MEC_DOORBELL_RANGE may
cause some APUs fail to enter gfxoff in certain user cases.

Signed-off-by: Yifan Zhang <yifan1.zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>