RDMA/mana_ib: Adding and deleting GIDs

Implement add_gid and del_gid for RNIC.
IPv4 and IPv6 addresses are supported.

Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
Link: https://lore.kernel.org/r/1712738551-22075-6-git-send-email-kotaranov@linux.microsoft.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>