Add support for the TK885D baseboard from TELE-DATA

The TK885D board uses a TQM885D module from TQ, this port adds an
own configuration file and adds a last_stage_init() method to
configure the two PHYs, depending on the phy_auto_nego environment
variable.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>