Merge tag 'u-boot-imx-20200108' of https://gitlab.denx.de/u-boot/custodians/u-boot-imx

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Add i.MX8MP SoC and EVK board
Update README for i.MX8MN EVK and fix mmc env
Add pca9450 driver
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Travis: https://travis-ci.org/sbabic/u-boot-imx/builds/634211885