Expose port function commands to enable / disable IPsec packet offloads,
this is used to control the port IPsec capabilities.

When IPsec packet is disabled for a function of the port (default),
function cannot offload IPsec packet operations (encapsulation and XFRM
policy offload). When enabled, IPsec packet operations can be offloaded
by the function of the port, which includes crypto operation
(Encrypt/Decrypt), IPsec encapsulation and XFRM state and policy
offload.

Example of a PCI VF port which supports IPsec packet offloads:

$ devlink port show pci/0000:06:00.0/1
    pci/0000:06:00.0/1: type eth netdev enp6s0pf0vf0 flavour pcivf pfnum 0 vfnum 0
        function:
        hw_addr 00:00:00:00:00:00 roce enable ipsec_packet disable

$ devlink port function set pci/0000:06:00.0/1 ipsec_packet enable

$ devlink port show pci/0000:06:00.0/1
    pci/0000:06:00.0/1: type eth netdev enp6s0pf0vf0 flavour pcivf pfnum 0 vfnum 0
        function:
        hw_addr 00:00:00:00:00:00 roce enable ipsec_packet enable
Signed-off-by: Dima Chumak <dchumak@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230825062836.103744-3-saeed@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>