[Bug] Fix compile issues for boards with custom matrix (#14323)

keyboards/keyboardio/model01/matrix.c

@@ -25,6 +25,17 @@
 static matrix_row_t rows[MATRIX_ROWS];
 #define ROWS_PER_HAND (MATRIX_ROWS / 2)
 
+// user-defined overridable functions
+
+__attribute__((weak)) void matrix_init_kb(void) { matrix_init_user(); }
+
+__attribute__((weak)) void matrix_scan_kb(void) { matrix_scan_user(); }
+
+__attribute__((weak)) void matrix_init_user(void) {}
+
+__attribute__((weak)) void matrix_scan_user(void) {}
+
+// helper functions
 inline
 uint8_t matrix_rows(void) {
   return MATRIX_ROWS;