drm/amdgpu: fix sdma doorbell issue on SDMA v6.0 and NBIO v7.7

This patch will fix sdma doorbell issue on SDMA v6.0 and NBIO v7.7.0.
NBIO v7.7.0 uses a new reg function -- Common SDMA to allow a common
doorbell range for all SDMA queues, this is different to the old
NBIO version. This patch will add configuration for CSDMA and enable
SDMA doorbell function.

Signed-off-by: Xiaojian Du <Xiaojian.Du@amd.com>
Reviewed-by: Tim Huang <Tim.Huang@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>