Move backlight config to data driven (#19910)

keyboards/mt/mt40/config.h

@@ -52,8 +52,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* COL2ROW, ROW2COL*/
 #define DIODE_DIRECTION COL2ROW
 
-#define BACKLIGHT_PIN D2
-
 /* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
 /* #define LOCKING_SUPPORT_ENABLE */
 /* Locking resynchronize hack */

keyboards/mt/mt40/info.json

@@ -8,6 +8,9 @@
     "pid": "0x422D",
     "device_version": "0.0.1"
   },
+  "backlight": {
+    "pin": "D2"
+  },
   "processor": "atmega32a",
   "bootloader": "bootloadhid",
   "community_layouts": ["planck_mit"],