teensy/mpconfigport: Drop unused root pointers.

pin_class_mapper and pin_class_map_dict are not used in the teensy port and
can be removed.

Signed-off-by: David Lechner <david@pybricks.com>

ports/teensy/mpconfigport.h

@@ -42,8 +42,6 @@ extern const struct _mp_obj_module_t pyb_module;
 #define MP_STATE_PORT MP_STATE_VM
 
 #define MICROPY_PORT_ROOT_POINTERS \
-    mp_obj_t pin_class_mapper; \
-    mp_obj_t pin_class_map_dict; \
     struct _pyb_uart_obj_t *pyb_stdio_uart; \
 
 // type definitions for the specific machine