EV3: Add empty path to default path to include frozen modules
(prefix the default unix path with a single colon to achieve this)
fixes
#define MICROPY_PORT_INIT_FUNC pybricks_init()
#define MICROPY_PORT_DEINIT_FUNC pybricks_deinit()
+#define MICROPY_PY_SYS_PATH_DEFAULT (":~/.micropython/lib:/usr/lib/micropython")
+
extern const struct _mp_obj_module_t pb_module_ev3brick;
extern const struct _mp_obj_module_t pb_module_ev3devices;
extern const struct _mp_obj_module_t pb_module_robotics;
