Merge branch 'mlx5 IPsec packet offload support (Part I)'

Leon Romanovsky says:

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This series follows previously sent "Extend XFRM core to allow packet
offload configuration" series [1].

It is first part with refactoring to mlx5 allow us natively extend
mlx5 IPsec logic to support both crypto and packet offloads.
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Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>