drm/radeon/kms/r600: fix forcing pci mode on agp cards

All we need to do on r6xx/r7xx is clear the RADEON_IS_AGP
flag; the rest is handled in r600.c

fixes fdo bug 23990:
http://bugs.freedesktop.org/show_bug.cgi?id=23990

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

drivers/gpu/drm/radeon/radeon_device.c

@@ -520,10 +520,13 @@ int radeon_device_init(struct radeon_device *rdev,
 
 	if (radeon_agpmode == -1) {
 		rdev->flags &= ~RADEON_IS_AGP;
-		if (rdev->family >= CHIP_RV515 ||
-		    rdev->family == CHIP_RV380 ||
-		    rdev->family == CHIP_RV410 ||
-		    rdev->family == CHIP_R423) {
+		if (rdev->family >= CHIP_R600) {
+			DRM_INFO("Forcing AGP to PCIE mode\n");
+			rdev->flags |= RADEON_IS_PCIE;
+		} else if (rdev->family >= CHIP_RV515 ||
+			   rdev->family == CHIP_RV380 ||
+			   rdev->family == CHIP_RV410 ||
+			   rdev->family == CHIP_R423) {
 			DRM_INFO("Forcing AGP to PCIE mode\n");
 			rdev->flags |= RADEON_IS_PCIE;
 			rdev->asic->gart_init = &rv370_pcie_gart_init;