Sync the mx7ulp device tree related files with the one from
NXP U-Boot vendor tree (imx_v2019.04_4.19.35_1.0.0).
The mainline support for i.MX7ULP is very premature at this stage.
We should probably re-sync with mainline Linux dts when it gets
in better shape, but for now sync with the U-Boot vendor code.
Signed-off-by: Fabio Estevam <festevam@gmail.com>