Change include guards in quantum/ to pragma once (#11239)

quantum/visualizer/lcd_backlight.h

@@ -22,8 +22,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef LCD_BACKLIGHT_H_
-#define LCD_BACKLIGHT_H_
+#pragma once
+
 #include <stdint.h>
 
 // Helper macros for storing hue, staturation and intensity as unsigned integers
@@ -41,5 +41,3 @@ uint8_t lcd_get_backlight_brightness(void);
 
 void lcd_backlight_hal_init(void);
 void lcd_backlight_hal_color(uint16_t r, uint16_t g, uint16_t b);
-
-#endif /* LCD_BACKLIGHT_H_ */