Fix IDEX broken endstop test (#21110)

Marlin/src/gcode/calibrate/G28.cpp

       };
     #endif
 
-    do_blocking_move_to_xy(1.5 * mlx * x_axis_home_dir, 1.5 * mly * home_dir(Y_AXIS), fr_mm_s);
+    do_blocking_move_to_xy(1.5 * mlx * x_axis_home_dir, 1.5 * mly * Y_HOME_DIR, fr_mm_s);
 
     endstops.validate_homing_move();
 

Marlin/src/module/endstops.h

   Z4_MIN, Z4_MAX
 };
 
-#define X_ENDSTOP (X_HOME_DIR < 0 ? X_MIN : X_MAX)
+#define X_ENDSTOP (x_home_dir(active_extruder) < 0 ? X_MIN : X_MAX)
 #define Y_ENDSTOP (Y_HOME_DIR < 0 ? Y_MIN : Y_MAX)
 #define Z_ENDSTOP (Z_HOME_DIR < 0 ? TERN(HOMING_Z_WITH_PROBE, Z_MIN, Z_MIN_PROBE) : Z_MAX)
 

Marlin/src/module/motion.h

     FORCE_INLINE void set_duplication_enabled(const bool dupe) { extruder_duplication_enabled = dupe; }
   #endif
 
-  FORCE_INLINE int x_home_dir(const uint8_t) { return home_dir(X_AXIS); }
+  FORCE_INLINE int x_home_dir(const uint8_t) { return X_HOME_DIR; }
 
 #endif