Refactor staryu to current standards and enable support for backlight keycodes (#5487)

keyboards/staryu/staryu.h

@@ -14,15 +14,19 @@ GNU General Public License for more details.
 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 KB_H
-#define KB_H
+#pragma once
 #include "quantum.h"
 
 #define LAYOUT( \
-	K00, K01, \
-	K10, K11, K12 \
+	     K00, K01, \
+	K10, K11, K12  \
 ) { \
 	{ K00, K01, K12, K11, K10 }, \
 }
 
+
+#ifdef BACKLIGHT_ENABLE
+
+void backlight_set_value(uint8_t index, uint8_t level);
+
 #endif