ipv6: Remove privacy config option.

The code for privacy extentions is very mature, and making it
configurable only gives marginal memory/code savings in exchange
for obfuscation and hard to read code via CPP ifdef'ery.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/linux/ipv6.h
Simple merge

diff --cc include/net/if_inet6.h
Simple merge

diff --cc net/ipv6/Kconfig
Simple merge

diff --cc net/ipv6/addrconf.c
Simple merge