Update submodule ecl to latest Wed Jun 24 00:39:40 UTC 2020

    - ecl in PX4/Firmware (fff83fd): PX4/PX4-ECL@a8bb8ea
    - ecl current upstream: PX4/PX4-ECL@e4b44f7
    - Changes: PX4/PX4-ECL@a8bb8ea...e4b44f7

    e4b44f7 2020-06-23 PX4 BuildBot - Update geo_lookup WMM  to latest Tue Jun 23 14:15:04 UTC 2020
4b746a3 2020-06-23 bresch - GPS Yaw: add consts and remove fusion starting message
2bafe9d 2020-06-22 bresch - GPS Yaw: wait to fuse at yaw at least once before declaring it faulty
51cd63d 2020-06-22 bresch - GPS Yaw: fall back to other yaw aiding source in case of bad data
fe2a9d3 2020-06-22 bresch - GPS Yaw: move isfinite checks in control.cpp
3c6790f 2020-06-22 bresch - GPS Yaw: Always reset Yaw when GPS Yaw fusion is starting
ff8b5ec 2020-06-21 kamilritz - Extract general functions into utils
fda30d8 2020-06-15 Daniel Agar - geo_lookup: expand latitude to +-80 degrees
109eca5 2020-06-15 Daniel Agar - geo_lookup: create simple python script to update tables
41b9e4f 2020-06-15 Daniel Agar - geo_lookup: move tables to separate file