mx7ulp: Move SoC base address to a common file

mx7ulp: Move SoC base address to a common file

SoC base addresses should better go into a common SoC file instead
of repeating the definition in each board file.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>