arm: socfpga: sockit: Use more relaxed DRAM timings

arm: socfpga: sockit: Use more relaxed DRAM timings

The currently present DRAM timings generated from GHRD 14.0 did
not work on SoCkit rev. D because they were too tight. Load the
DRAM timings from GHRD 13.0 which are more relaxed and work with
SoCkit rev. D.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Chin Liang See <clsee@altera.com>