omap4: make SDRAM init work for ES1.0 silicon

SDRAM init was not working on ES1.0 due to a programming
error. A pointer that was passed by value to a function
was set in function emif_get_device_details(), but the effect
wouldn't be seen in the calling function. The issue came
out while testing for ES1.0 because ES1.0 doesn't have any
SDRAM chips connected to CS1

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>