Migrate SPLIT_HAND_PIN to json (#23924)

keyboards/recompile_keys/cocoa40/config.h

@@ -1,20 +0,0 @@
-/*
-Copyright 2019 'Naoto Takai'
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-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/>.
-*/
-
-#pragma once
-
-#define SPLIT_HAND_PIN D3

keyboards/recompile_keys/cocoa40/keyboard.json

@@ -23,6 +23,9 @@
     "diode_direction": "COL2ROW",
     "split": {
         "enabled": true,
+        "handedness": {
+            "pin": "D3"
+        },
         "soft_serial_pin": "D2"
     },
     "processor": "atmega32u4",