OK, I would now say that I am finally at a point where I can test the RAM. I loaded the LCDK OMAP-L138 GEL file and with that GEL I am able to write to the correct RAM location. I was also able to load the ARM eXp RAM TEST and that successfully passed.
I'll review the LCDK GEL file and compare it to my latest attempt but hopefully this will help anyone else who decides to use DDR2.
I still need to test NAND and SDMMC but those are connected just like the EVM so hopefully now that RAM is configured properly those will also pass.