net/mlx5e: TC, initialize branch flow attributes

net/mlx5e: TC, initialize branch flow attributes

Initialize flow attribute for drop, accept, pipe and jump branching actions.

Instantiate a flow attribute instance according to the specified branch
control action. Store the branching attributes on the branching action
flow attribute during the parsing phase. Then, during the offload phase,
allocate the relevant mod header objects to the branching actions.

Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20221203221337.29267-8-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>