Don't define RGBLED_NUM in let-split khord keymap

It's already defined correctly by the parent keyboard project, and was
causing problems for rev1, where the pin is different.

keyboards/lets_split/keymaps/khord/config.h

@@ -20,9 +20,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define USE_SERIAL
 #define EE_HANDS
 
-#undef RGBLED_NUM
 #define RGBLIGHT_ANIMATIONS
-#define RGBLED_NUM 12
 
 #ifdef SUBPROJECT_rev1
     #include "../../rev1/config.h"