siemens: update DDR3 parameters for dxr2

* add parameters for factory and print them at start up to
   facilitate control of right DDR3 settings in EEPROM.

 * cosmetic changes in a couple of printfs

Signed-off-by: Samuel Egli <samuel.egli@siemens.com>
Cc: Roger Meier <r.meier@siemens.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Wolfgang Denk <wd@denx.de>