add conditional for planck-mitch keymap

keyboards/planck/keymaps/mitch/config.h

@@ -1,2 +1,6 @@
 #include "../../config.h"
 #define PREVENT_STUCK_MODIFIERS
+
+// for the broken board
+#undef MATRIX_COL_PINS
+#define MATRIX_COL_PINS { F1, F0, B0, B2, F4, F5, F6, F7, D4, D6, B4, D7 }