drm/radeon: add additional pci revision to dpm workaround

New variant.

Signed-off-by: Alex Deucher <[e-mail]>
Cc: [e-mail]

drivers/gpu/drm/radeon/si_dpm.c

···
 		    (rdev->pdev->revision == 0x80) ||
 		    (rdev->pdev->revision == 0x81) ||
 		    (rdev->pdev->revision == 0x83) ||
+		    (rdev->pdev->revision == 0x87) ||
 		    (rdev->pdev->device == 0x6604) ||
 		    (rdev->pdev->device == 0x6605)) {
 			max_sclk = 75000;