Revert "omap2: overclock ram."

Previous configuration was rebooting the device 2-4 minutes into Stability Test.

Thanks @franciscofranco and @osm0sis

This reverts commit b40fefdf208b81b9d2fc5f21b01b44f321b398a2.

Signed-off-by: Dan Trifan <jimsth@gmail.com>