net/mlx4_core: Translate guest B0 steering rules to DMFS

The different steering modes are global to the device, with DMFS
being introduced after SRIOV was merged. Hence, SRIOV guests running
legacy / older Linux kernels or non-Linux drivers may provide
B0 steering directives when the hypervisor is using DMFS and fail.

Under B0 only L2 steering rules are allowed, hence B0 is a subset of DMFS.
Use this fact to enable such legacy guests to run by modifying the SRIOV
B0 steering wrapper to translate guest B0 directives to DMFS ones when
the device uses DMFS. The translated B0 rule has to be kept in the
resource tracker as a B0 object to allow for lookup in case of detach.

Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>