Update submodule ecl to latest Mon Jun 10 00:39:54 UTC 2019

    - ecl in PX4/Firmware (c90a1de863397aad9ea126d4e87f6548242d7ef8): PX4/PX4-ECL@54ac147
    - ecl current upstream: PX4/PX4-ECL@0f49eb3
    - Changes: PX4/PX4-ECL@54ac147...0f49eb3

    0f49eb3 2019-05-24 RomanBapst - fixed method which calculates validity of terrain estimate
cd34ab8 2019-05-24 Daniel Agar - mathlib delete floorf in favor of math.h
340d85a 2019-05-27 Robert de Vries - EKF: fix variable names in estimator_interface.h
90b4c7c 2019-05-24 Matthias Grob - mathlib: fix floorf indentation
710c529 2019-05-23 Sebastian Verling - fixed calculation of magentic table values by using floor instead of int casting