Change keyboard level include guards to pragma once (#14248)

* Change keyboard level include guards to `pragma once`

And clean up a lot of layout macros

* Oops

* Remove dangling endif

keyboards/converter/sun_usb/config.h

@@ -15,8 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef CONFIG_H
-#define CONFIG_H
+#pragma once
 
 #define VENDOR_ID       0xFEED
 #define PRODUCT_ID      0x3333
@@ -81,5 +80,3 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
     /* idle */ \
     SERIAL_SOFT_TXD_ON(); \
 } while (0)
-
-#endif