Leave hardware-specified preferred modes alone when user preference exists.

Instead of removing the preference bit marking the hardware declared mode
preference, leave it in place and just move the user preferred mode to the
front of the list while marking it with the USERPREF bit which will cause it
to be selected by the initial mode selection code.

hw/xfree86/modes/xf86Crtc.c

@@ -1417,9 +1417,8 @@ xf86ProbeOutputModes (ScrnInfoPtr scrn, int maxX, int maxY)
 			output->probed_modes = mode;
 		    }
 		    mode->type |= (M_T_PREFERRED|M_T_USERPREF);
+		    break;
 		}
-		else
-		    mode->type &= ~M_T_PREFERRED;
 	    }
 	}