Improve SPI TFT and XPT2046 support (HAL rework)

Marlin/Configuration_adv.h

@@ -2978,9 +2978,9 @@
    * but you can override or define them here.
    */
   //#define TMC_USE_SW_SPI
-  //#define TMC_SW_MOSI       -1
-  //#define TMC_SW_MISO       -1
-  //#define TMC_SW_SCK        -1
+  //#define TMC_SPI_MOSI      -1
+  //#define TMC_SPI_MISO      -1
+  //#define TMC_SPI_SCK       -1
 
   // @section tmc/serial
 

Marlin/Marlin.ino

@@ -27,7 +27,7 @@ Configuration
   - https://github.com/MarlinFirmware/Configurations
     Example configurations for several printer models.
 
-  - https://www.youtube.com/watch?v=3gwWVFtdg-4
+  - https://youtu.be/3gwWVFtdg-4
     A good 20-minute overview of Marlin configuration by Tom Sanladerer.
     (Applies to Marlin 1.0.x, so Jerk and Acceleration should be halved.)
     Also... https://www.google.com/search?tbs=vid%3A1&q=configure+marlin

Marlin/src/HAL/AVR/HAL.cpp

@@ -61,6 +61,12 @@ void save_reset_reason() {
   wdt_disable();
 }
 
+#include "registers.h"
+
+MarlinHAL::MarlinHAL() {
+  TERN_(HAL_AVR_DIRTY_INIT, _ATmega_resetperipherals()); // Clean-wipe the device state.
+}
+
 void MarlinHAL::init() {
   // Init Servo Pins
   #define INIT_SERVO(N) OUT_WRITE(SERVO##N##_PIN, LOW)
@@ -78,6 +84,25 @@ void MarlinHAL::init() {
   #endif
 
   init_pwm_timers();   // Init user timers to default frequency - 1000HZ
+
+  #if defined(BEEPER_PIN) || ENABLED(ATMEGA_NO_BEEPFIX)
+    // Make sure no alternative is locked onto the BEEPER.
+    // This fixes the issue where the ATmega is constantly beeping.
+    // Might destroy other peripherals using the pin; to circumvent that please undefine one of the above things!
+    // The true culprit is the AVR ArduinoCore that enables peripherals redundantly.
+    // (USART1 on the GeeeTech GT2560)
+    _ATmega_savePinAlternate(BEEPER_PIN);
+
+    OUT_WRITE(BEEPER_PIN, LOW);
+  #endif
+
+    // EXAMPLE: beep loop using proper pin state.
+  #if 0 && defined(BEEPER_PIN)
+    while (true) {
+      OUT_WRITE(BEEPER_PIN, HIGH); delay(1000);
+      OUT_WRITE(BEEPER_PIN, LOW);  delay(2000);
+    }
+  #endif
 }
 
 void MarlinHAL::reboot() {

Marlin/src/HAL/AVR/HAL.h

@@ -187,7 +187,7 @@ class MarlinHAL {
 public:
 
   // Earliest possible init, before setup()
-  MarlinHAL() {}
+  MarlinHAL();
 
   // Watchdog
   static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});