Engicam i.Core STM32MP1 SODIMM SoM has mounted 1x4Gb DDR3 which has 32bits width 528000Khz frequency. Add DDR configuration via dtsi. Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com> Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>