TQM8548: Basic support for the TQM8548 modules

This patch adds basic support for the TQM8548 module from TQ-Components
(http://www.tqc.de/

) including DDR2 SDRAM initialisation and support for
eTSEC 3 and 4

Furthermore Flash buffer write has been enabled to speed up output to
the Flash by approx. a factor of 10.

Signed-off-by: Thomas Waehner <thomas.waehner@tqs.de>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>