Apply #pragma once, misc cleanup (#12322)

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

Marlin/src/HAL/HAL_STM32F1/HAL.h

@@ -20,14 +20,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#pragma once
 
 /**
  * HAL for stm32duino.com based on Libmaple and compatible (STM32F1)
  */
 
-#ifndef _HAL_STM32F1_H
-#define _HAL_STM32F1_H
-
 #define CPU_32_BIT
 #undef DEBUG_NONE
 
@@ -251,5 +249,3 @@ void HAL_enable_AdcFreerun(void);
 
 #define JTAG_DISABLE() afio_cfg_debug_ports(AFIO_DEBUG_SW_ONLY)
 #define JTAGSWD_DISABLE() afio_cfg_debug_ports(AFIO_DEBUG_NONE)
-
-#endif // _HAL_STM32F1_H