Add core/fallback encoder behaviour (#20320)

keyboards/ck60i/ck60i.c

@@ -16,15 +16,3 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "ck60i.h"
-
-bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!encoder_update_user(index, clockwise)) return false;
-    if (index == 0) { /* First encoder */
-        if (clockwise) {
-            tap_code(KC_VOLU);
-        } else {
-            tap_code(KC_VOLD);
-        }
-    }
-    return true;
-}