imx: sync with kernel device tree for Phycore SoM

Sync the Linux Kernel 5.4-rc6 device tree for Phytec Phycore
SoM and Segin board based on imx6UL and imx6ULL.

Changes includes Phytec naming convention for the devicetree files.

Signed-off-by: Parthiban Nallathambi <parthitce@gmail.com>
Acked-by: Peng Fan <peng.fan@nxp.com>