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

quantum/audio/voices.h

@@ -13,6 +13,9 @@
  * 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
+
 #include <stdint.h>
 #include <stdbool.h>
 #if defined(__AVR__)
@@ -21,14 +24,11 @@
 #include "wait.h"
 #include "luts.h"
 
-#ifndef VOICES_H
-#    define VOICES_H
-
 float voice_envelope(float frequency);
 
 typedef enum {
     default_voice,
-#    ifdef AUDIO_VOICES
+#ifdef AUDIO_VOICES
     something,
     drums,
     butts_fader,
@@ -41,12 +41,10 @@ typedef enum {
 // duty_fourth_down,
 // duty_third_down,
 // duty_fifth_third_down,
-#    endif
+#endif
     number_of_voices  // important that this is last
 } voice_type;
 
 void set_voice(voice_type v);
 void voice_iterate(void);
 void voice_deiterate(void);
-
-#endif