make QUICKHOME configureable

Marlin/Configuration.h

@@ -214,6 +214,7 @@ const bool Z_ENDSTOPS_INVERTING = true; // set to true to invert the logic of th
 #define X_HOME_RETRACT_MM 5 
 #define Y_HOME_RETRACT_MM 5 
 #define Z_HOME_RETRACT_MM 1 
+#define QUICK_HOME  //if this is defined, if both x and y are to be homed, a diagonal move will be performed initially.
 
 #define AXIS_RELATIVE_MODES {false, false, false, false}