Change include guards in tmk_core/ and drivers/ to pragma once (#11240)

tmk_core/protocol/ps2.h

@@ -35,8 +35,7 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
-#ifndef PS2_H
-#define PS2_H
+#pragma once
 
 #include <stdbool.h>
 #include "wait.h"
@@ -138,5 +137,3 @@ static inline void inhibit(void) {
     clock_lo();
     data_hi();
 }
-
-#endif