Revert "Backport ipv6 addrconf.c and dependencies from 3.0.101"

This reverts commit a25b2c37e820bc597d4712263a269814ea87ac46 as
it is causing rare kernel-panics on IPv6 enabled networks.

Additionally CONFIG_IPV6_ROUTER_RS_PRD is set to n which disables
the motorola "enhancements" originally responsible for the
backport.

Change-Id: I0d7d16e7ad758f55bda7446665897697919d0604