Revert "net: team: use IFF_NO_ADDRCONF flag to prevent ipv6 addrconf"

This reverts commit 0aa64df3.

Currently IFF_NO_ADDRCONF is used to prevent all ipv6 addrconf for the
slave ports of team, bonding and failover devices and it means no ipv6
packets can be sent out through these slave ports. However, for team
device, "nsna_ping" link_watch requires ipv6 addrconf. Otherwise, the
link will be marked failure. This patch removes the IFF_NO_ADDRCONF
flag set for team port, and we will fix the original issue in another
patch, as Jakub suggested.

Fixes: 0aa64df3

 ("net: team: use IFF_NO_ADDRCONF flag to prevent ipv6 addrconf")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/63e09531fc47963d2e4eff376653d3db21b97058.1673980932.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>