Update submodule ecl to latest Mon Sep 2 00:38:06 UTC 2019

    - ecl in PX4/Firmware (5d2b894): PX4/PX4-ECL@62fa464
    - ecl current upstream: PX4/PX4-ECL@be368f3
    - Changes: PX4/PX4-ECL@62fa464...be368f3

    be368f3 2019-08-28 kamilritz - Update comment
c5abfe6 2019-08-28 kamilritz - remove canonicalize and adapt comments
67512d8 2019-08-22 kamilritz - Update matrix library for CI
a2ff415 2019-08-22 kamilritz - Fix get frame aligning quaternion function
53eac6e 2019-08-21 kamilritz - Canonicalize alignment quaternion
933c32c 2019-08-20 kamilritz - Enable local frame alignment also without using it
ea352a6 2019-08-20 kamilritz - Dont use mag suffix for magnitude
05196db 2019-08-20 kamilritz - Fix alignment of local frame