drm/radeon/kms: mark 3D power states as performance

Fixes lack of power saving with multiple heads on
some desktop cards.

Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=16474

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_atombios.c

@@ -2064,6 +2064,11 @@ void radeon_atombios_get_power_modes(struct radeon_device *rdev)
 						rdev->pm.power_state[state_index].type =
 							POWER_STATE_TYPE_PERFORMANCE;
 						break;
+					case ATOM_PPLIB_CLASSIFICATION_UI_NONE:
+						if (misc2 & ATOM_PPLIB_CLASSIFICATION_3DPERFORMANCE)
+							rdev->pm.power_state[state_index].type =
+								POWER_STATE_TYPE_PERFORMANCE;
+						break;
 					}
 					rdev->pm.power_state[state_index].flags = 0;
 					if (misc & ATOM_PPLIB_SINGLE_DISPLAY_ONLY)