Make the fan thresholds configurable

Firmware/ultralcd.cpp

@@ -7611,10 +7611,10 @@ static void lcd_selftest_measure_fans(uint8_t delay, uint8_t col, uint8_t row) {
 static FanCheck lcd_selftest_fan_auto(uint8_t _fan)
 {
     // speed threshold to differentiate between extruder and print fan
-    static const int printFanThr = 70; // >=4200 RPM
+    static const int printFanThr = FANCHECK_AUTO_PRINT_FAN_THRS; // >= FANCHECK_AUTO_PRINT_FAN_THRS RPS
 
     // speed threshold to mark a fan as failed
-    static const int failThr = 20; // <1200 RPM would mean either a faulty Noctua, Altfan or print fan
+    static const int failThr = FANCHECK_AUTO_FAIL_THRS; // < FANCHECK_AUTO_FAIL_THRS RPM would mean either a faulty Noctua, Altfan or print fan
 
 	switch (_fan) {
 	case 0:

Firmware/variants/1_75mm_MK25-RAMBo10a-E3Dv6full.h

@@ -219,6 +219,9 @@
 #define EXTRUDER_AUTO_FAN_TEMPERATURE 50
 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
+#define FANCHECK_AUTO_PRINT_FAN_THRS 70 //[RPS] - Used during selftest to identify swapped fans automatically
+#define FANCHECK_AUTO_FAIL_THRS 20 //[RPS] - Used during selftest to identify a faulty fan
+
 
 /*------------------------------------
  LOAD/UNLOAD FILAMENT SETTINGS

Firmware/variants/1_75mm_MK25-RAMBo13a-E3Dv6full.h

@@ -220,6 +220,9 @@
 #define EXTRUDER_AUTO_FAN_TEMPERATURE 50
 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
+#define FANCHECK_AUTO_PRINT_FAN_THRS 70 //[RPS] - Used during selftest to identify swapped fans automatically
+#define FANCHECK_AUTO_FAIL_THRS 20 //[RPS] - Used during selftest to identify a faulty fan
+
 
 /*------------------------------------
  LOAD/UNLOAD FILAMENT SETTINGS

Firmware/variants/1_75mm_MK25S-RAMBo10a-E3Dv6full.h

@@ -219,6 +219,9 @@
 #define EXTRUDER_AUTO_FAN_TEMPERATURE 50
 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
+#define FANCHECK_AUTO_PRINT_FAN_THRS 70 //[RPS] - Used during selftest to identify swapped fans automatically
+#define FANCHECK_AUTO_FAIL_THRS 20 //[RPS] - Used during selftest to identify a faulty fan
+
 
 /*------------------------------------
  LOAD/UNLOAD FILAMENT SETTINGS

Firmware/variants/1_75mm_MK25S-RAMBo13a-E3Dv6full.h

@@ -220,6 +220,9 @@
 #define EXTRUDER_AUTO_FAN_TEMPERATURE 50
 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
+#define FANCHECK_AUTO_PRINT_FAN_THRS 70 //[RPS] - Used during selftest to identify swapped fans automatically
+#define FANCHECK_AUTO_FAIL_THRS 20 //[RPS] - Used during selftest to identify a faulty fan
+
 
 /*------------------------------------
  LOAD/UNLOAD FILAMENT SETTINGS

Firmware/variants/1_75mm_MK3-EINSy10a-E3Dv6full.h

@@ -355,6 +355,8 @@
 #define EXTRUDER_AUTO_FAN_TEMPERATURE 50
 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
+#define FANCHECK_AUTO_PRINT_FAN_THRS 70 //[RPS] - Used during selftest to identify swapped fans automatically
+#define FANCHECK_AUTO_FAIL_THRS 20 //[RPS] - Used during selftest to identify a faulty fan
 
 
 /*------------------------------------

Firmware/variants/1_75mm_MK3S-EINSy10a-E3Dv6full.h

@@ -359,6 +359,8 @@
 #define EXTRUDER_ALTFAN_DETECT
 #define EXTRUDER_ALTFAN_SPEED_SILENT 128
 
+#define FANCHECK_AUTO_PRINT_FAN_THRS 70 //[RPS] - Used during selftest to identify swapped fans automatically
+#define FANCHECK_AUTO_FAIL_THRS 20 //[RPS] - Used during selftest to identify a faulty fan
 
 
 /*------------------------------------