IPVS: Add IPv6 support to LBLC/LBLCR schedulers

Add IPv6 support to LBLC and LBLCR schedulers. These were the last
schedulers without IPv6 support, but we might want to keep the
supports_ipv6 flag in the case of future schedulers without IPv6
support.

Signed-off-by: Julius Volz <julius.volz@gmail.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>