ARM: imx: Update Data Modul i.MX8M Mini eDM SBC DRAM timing

Adjust the DRAM timing settings for this board per ones provided
by hardware department. The change is applied to the LPDDR4 MR11
register CA ODT configuration, from RZQ/6 to RZQ/3, which fixes
stability issues on subset of boards. The DDR PHY PIE block has
been updated accordingly.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Fabio Estevam <festevam@denx.de>