u-boot ethernet changes for prowl

by danielmentz@
configure the QCA8337N Ethernet switch to "Mode 5" as described in the
datasheet where RMGII 0 is connected to MAC0 of the Ethernet switch and
RGMII 1 is routed straight to PHY 4 (WAN port).

Change-Id: Ida68072f2d6443b6bd5b556c45c28a980592f320
3 files changed