Move RGBLED_SPLIT to data driven (#21113)

Co-authored-by: Joel Challis <git@zvecr.com>

keyboards/flxlb/zplit/config.h

@@ -31,7 +31,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* ws2812 RGB LED */
 #define RGBLED_NUM 16
 #define RGBLIGHT_LED_MAP { 0, 1, 2, 3, 4, 5, 6, 7, 15, 14, 13, 12, 11, 10, 9, 8}
-#define RGBLED_SPLIT { 8, 8 }
 #define RGBLIGHT_SPLIT
 #define RGBLIGHT_EFFECT_BREATHING
 #define RGBLIGHT_EFFECT_RAINBOW_MOOD

keyboards/flxlb/zplit/info.json

@@ -18,6 +18,9 @@
             {"pin_a": "B0", "pin_b": "D2"}
         ]
     },
+    "rgblight": {
+        "split_count": [8, 8]
+    },
     "ws2812": {
         "pin": "D3"
     },