net/mlx5e: Create symmetric IPsec RX and TX flow steering structs

Remove AF family obfuscation by creating symmetric structs for RX and
TX IPsec flow steering chains. This simplifies to us low level IPsec
FS creation logic without need to dig into multiple levels of structs.

Reviewed-by: Raed Salem <raeds@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>