Apply #pragma once, misc cleanup (#12322)

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

Marlin/src/HAL/HAL_ESP32/HAL.h

@@ -16,14 +16,12 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+#pragma once
 
 /**
  * Description: HAL for Espressif ESP32 WiFi
  */
 
-#ifndef _HAL_ESP32_H
-#define _HAL_ESP32_H
-
 #define CPU_32_BIT
 
 // --------------------------------------------------------------------------
@@ -123,5 +121,3 @@ void HAL_adc_start_conversion (uint8_t adc_pin);
 #define HAL_INIT 1
 void HAL_idletask(void);
 void HAL_init(void);
-
-#endif // _HAL_ESP32_H