Remove useless "ifdef KEYBOARD_*" (#20078)

Co-authored-by: Nick Brassel <nick@tzarc.org>

keyboards/keebio/quefrency/rev3/rev3.c

@@ -14,7 +14,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "quefrency.h"
+#include "rev3.h"
 #include "split_util.h"
 
 void matrix_init_kb(void) {

keyboards/keebio/quefrency/rev3/rev3.h

@@ -16,7 +16,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #pragma once
 
-#include "quefrency.h"
 #include "quantum.h"
 
 #define LAYOUT_60( \