Apply #pragma once, misc cleanup (#12322)

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

Marlin/src/HAL/HAL_STM32F1/fastio_Stm32f1.h

@@ -20,15 +20,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#pragma once
 
 /**
  * Fast I/O interfaces for STM32F1
  * These use GPIO functions instead of Direct Port Manipulation, as on AVR.
  */
 
-#ifndef _FASTIO_STM32F1_H
-#define _FASTIO_STM32F1_H
-
 #include <libmaple/gpio.h>
 
 #define READ(IO)              (PIN_MAP[IO].gpio_device->regs->IDR & (1U << PIN_MAP[IO].gpio_bit) ? HIGH : LOW)
@@ -52,5 +50,3 @@
 
 #define PWM_PIN(p) true
 #define USEABLE_HARDWARE_PWM(p) PWM_PIN(p)
-
-#endif // _FASTIO_STM32F1_H