l1 controller: simpler way of doing slew rate limiting
l1 controller: simpler way of doing slew rate limiting

Signed-off-by: Roman <019237760eff64d50a7eec108f84e3d8840aac17@gmail.com>

PX4/ecl,PX4/ecl,PX4/ecl,PX4/ecl,PX4/ecl