drm/radeon: add additional pci revision to dpm workaround

[ Upstream commit 8729675c00a8d13cb2094d617d70a4a4da7d83c5 ]

New variant.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>