Merge pull request #8460 from Bob-the-Kuhn/E0-autofan

2.0.x E0 auto fan fixes for LP1768

Marlin/src/module/temperature.cpp

 #if HAS_AUTO_FAN
 
   void Temperature::checkExtruderAutoFans() {
-    static const int8_t fanPin[] PROGMEM = { E0_AUTO_FAN_PIN, E1_AUTO_FAN_PIN, E2_AUTO_FAN_PIN, E3_AUTO_FAN_PIN, E4_AUTO_FAN_PIN };
+    static const pin_t fanPin[] PROGMEM = { E0_AUTO_FAN_PIN, E1_AUTO_FAN_PIN, E2_AUTO_FAN_PIN, E3_AUTO_FAN_PIN, E4_AUTO_FAN_PIN };
     static const uint8_t fanBit[] PROGMEM = {
                     0,
       AUTO_1_IS_0 ? 0 :               1,
 
     uint8_t fanDone = 0;
     for (uint8_t f = 0; f < COUNT(fanPin); f++) {
-      int8_t pin = pgm_read_byte(&fanPin[f]);
+      #ifdef ARDUINO
+        pin_t pin = pgm_read_byte(&fanPin[f]);
+      #else
+        pin_t pin = fanPin[f];
+      #endif
       const uint8_t bit = pgm_read_byte(&fanBit[f]);
       if (pin >= 0 && !TEST(fanDone, bit)) {
         uint8_t newFanSpeed = TEST(fanState, bit) ? EXTRUDER_AUTO_FAN_SPEED : 0;