drm/amdgpu: fix doorbell regression

drm/amdgpu: fix doorbell regression

[ Upstream commit 705d0480e6ae5a73ca3a9c04316d0678e19a46ed ]

This patch adds a missed handling of PL domain doorbell while
handling VRAM faults.

Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Fixes: a6ff969fe9cb ("drm/amdgpu: fix visible VRAM handling during faults")
Reviewed-by: Christian Koenig <christian.koenig@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>