[ATM]: allow bind() on point-to-multpoint svcs (from Martin Whitaker...

[ATM]: allow bind() on point-to-multpoint svcs (from Martin Whitaker <martin_whitaker@ntlworld.com>)

Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>