ramips: Drop hacky switch workaround for failsafe on rt3x5x and rt5350.

The new rt3050 switch driver doesn't have problems with TCP when not
using VLANs.

This piece of code also broke failsafe for all routers where the LAN
port is not wired to port 0 of the internal switch.

Signed-off-by: Vittorio Gambaletta <openwrt@vittgam.net>

SVN-Revision: 49293