Apply #pragma once, misc cleanup (#12322)

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

Marlin/src/HAL/HAL_LPC1768/HAL.h

@@ -19,15 +19,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#pragma once
 
 /**
  * HAL_LPC1768/HAL.h
  * Hardware Abstraction Layer for NXP LPC1768
  */
 
-#ifndef _HAL_LPC1768_H_
-#define _HAL_LPC1768_H_
-
 #define CPU_32_BIT
 #define HAL_INIT
 
@@ -156,5 +154,3 @@ int16_t PARSED_PIN_INDEX(const char code, const int16_t dval);
 
 #define HAL_IDLETASK 1
 void HAL_idletask(void);
-
-#endif // _HAL_LPC1768_H_