OMAP5: emif/ddr: Change emif settings as required for ES1.0 silicon.

The OMAP5 silicon has new DDR PHY design, which includes a external PHY
as well. So configuring the ext PHY parameters here. Also the EMIF timimg
registers and a couple of DDR mode registers needs to be updated based on
the testing from the actual silicon.

Signed-off-by: R Sricharan <r.sricharan@ti.com>