[Keyboard] YMD75 rev 3: fix BACKLIGHT_PIN (#11172)

* YMD75 rev 3:  fix BACKLIGHT_PIN

Update backlight LED pin used by QMK to control the per-key backlight for YMD75 rev 3

* YMD75 rev 3: fix BACKLIGHT_PIN - fix comments

* YMD75: move BACKLIGHT_PIN definitions to the respective versions

Signed-off-by: Nathan13888 <29968201+Nathan13888@users.noreply.github.com>

keyboards/ymd75/config.h

@@ -27,7 +27,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MANUFACTURER    YMDK
 #define PRODUCT         YMD75 / MT84
 
-#define BACKLIGHT_PIN D4
 #define BACKLIGHT_LEVELS 12
 
 #define RGB_DI_PIN E2

keyboards/ymd75/rev1/config.h

@@ -24,5 +24,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COLS 15
 #define MATRIX_ROW_PINS { B0, B1, B2, B3, B4, B5, B6, B7 }
 #define MATRIX_COL_PINS { A0, A1, A2, A3, A4, A5, A6, A7, C7, C6, C5, C4, C3, C2, D7 }
+#define BACKLIGHT_PIN D4
 #define DIODE_DIRECTION COL2ROW
 #define DEVICE_VER      0x0100

keyboards/ymd75/rev2/config.h

@@ -5,5 +5,6 @@
 #define MATRIX_COLS 15
 #define MATRIX_ROW_PINS { B7, B6, B5, B4, B3, B0 }
 #define MATRIX_COL_PINS { A0, A1, A2, A3, A4, A5, A6, A7, C7, C6, C5, C4, C3, C2, D7 }
+#define BACKLIGHT_PIN D4
 #define DIODE_DIRECTION COL2ROW
 #define DEVICE_VER      0x0200

keyboards/ymd75/rev3/config.h

@@ -4,6 +4,7 @@
 #define MATRIX_COLS 9
 #define MATRIX_ROW_PINS { B7, B3, B2, B1, B0, E6, F0, F1, F4, F5, F6, F7 }
 #define MATRIX_COL_PINS { D0, D1, D2, D3, D5, D4, D6, D7, B4 }
+#define BACKLIGHT_PIN B6 // change the backlight pin that has since changed in Rev 3
 #define DIODE_DIRECTION ROW2COL
 #define DEVICE_VER      0x0300
 #define RGBLIGHT_EFFECT_KNIGHT_OFFSET 4