Revert "drm/amdgpu: Fix bugs in setting CP RB/MEC DOORBELL_RANGE registers"

The original change caused a regression, so revert it until the new fix
is ready.

BUG: https://bugs.freedesktop.org/show_bug.cgi?id=109650



This reverts commit 764c85fef41722db0f21558c6c2fb38bee172d19.

Signed-off-by: Yong Zhao <Yong.Zhao@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>