net/mlx5: Implement alias object allow and create functions

Add functions which allow one vhca to access another vhca object,
and functions that creates an alias object or destroys it.

Together they can be used to create cross vhca flow table that is able
jump from the steering domain that is managed by one vport,
to the steering domain on a different vport.

Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Link: https://lore.kernel.org/r/f45a9c85319fa783186b8988abcd64955b5f2a0c.1695296682.git.leon@kernel.org


Signed-off-by: Leon Romanovsky <leon@kernel.org>