Set up DIAG endstops for BTT SKR 1.4 / 1.4 Turbo (#16727)

Marlin/src/pins/lpc1768/pins_BTT_SKR_V1_4.h

@@ -38,11 +38,52 @@
 #define SERVO0_PIN         P2_00
 
 //
+// TMC StallGuard DIAG pins
+//
+#define X_DIAG_PIN         P1_29   // X-STOP
+#define Y_DIAG_PIN         P1_28   // Y-STOP
+#define Z_DIAG_PIN         P1_27   // Z-STOP
+#define E0_DIAG_PIN        P1_26   // E0DET
+#define E1_DIAG_PIN        P1_25   // E1DET
+
+//
 // Limit Switches
 //
-#define X_STOP_PIN         P1_29
-#define Y_STOP_PIN         P1_28
-#define Z_STOP_PIN         P1_27
+#if X_STALL_SENSITIVITY
+  #if X_HOME_DIR < 0
+    #define X_MIN_PIN      X_DIAG_PIN
+    #define X_MAX_PIN      P1_26   // E0DET
+  #else
+    #define X_MAX_PIN      X_DIAG_PIN
+    #define X_MIN_PIN      P1_26   // E0DET
+  #endif
+#else
+  #define X_STOP_PIN       P1_29   // X-STOP
+#endif
+
+#if Y_STALL_SENSITIVITY
+  #if Y_HOME_DIR < 0
+    #define Y_MIN_PIN      Y_DIAG_PIN
+    #define Y_MAX_PIN      P1_25   // E1DET
+  #else
+    #define Y_MAX_PIN      Y_DIAG_PIN
+    #define Y_MIN_PIN      P1_25   // E1DET
+  #endif
+#else
+  #define Y_STOP_PIN       P1_28   // Y-STOP
+#endif
+
+#if Z_STALL_SENSITIVITY
+  #if Z_HOME_DIR < 0
+    #define Z_MIN_PIN      Z_DIAG_PIN
+    #define Z_MAX_PIN      P1_24   // PWRDET
+  #else
+    #define Z_MAX_PIN      Z_DIAG_PIN
+    #define Z_MIN_PIN      P1_24   // PWRDET
+  #endif
+#else
+  #define Z_STOP_PIN       P1_27   // Z-STOP
+#endif
 
 //
 // Z Probe (when not Z_MIN_PIN)
@@ -54,21 +95,21 @@
 //
 // Filament Runout Sensor
 //
-#define FIL_RUNOUT_PIN     P1_26
-#define FIL_RUNOUT2_PIN    P1_25
+#define FIL_RUNOUT_PIN     P1_26   // E0DET
+#define FIL_RUNOUT2_PIN    P1_25   // E1DET
 
 //
 // Power Supply Control
 //
 #ifndef PS_ON_PIN
-  #define PS_ON_PIN        P1_00
+  #define PS_ON_PIN        P1_00   // PWRDET
 #endif
 
 //
 // Power Loss Detection
 //
 #ifndef POWER_LOSS_PIN
-  #define POWER_LOSS_PIN   P1_00
+  #define POWER_LOSS_PIN   P1_00   // PWRDET
 #endif
 
 //