drm/amdgpu: move nbio sdma_doorbell_range() into sdma code for vega

drm/amdgpu: move nbio sdma_doorbell_range() into sdma code for vega

This mirrors what we do for other asics and this way we are
sure the sdma doorbell range is properly initialized.

There is a comment about the way doorbells on gfx9 work that
requires that they are initialized for other IPs before GFX
is initialized.  However, the statement says that it applies to
multimedia as well, but the VCN code currently initializes
doorbells after GFX and there are no known issues there.  In my
testing at least I don't see any problems on SDMA.

This is a prerequisite for fixing the Unsupported Request error
reported through AER during driver load.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216373
The error was unnoticed before and got visible because of the commit
referenced below. This doesn't fix anything in the commit below, rather
fixes the issue in amdgpu exposed by the commit. The reference is only
to associate this commit with below one so that both go together.

Fixes: 8795e182b02d ("PCI/portdrv: Don't disable AER reporting in get_port_device_capability()")
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org