net/mlx5: fix host physical function representor naming

net/mlx5: fix host physical function representor naming

The new kernel adds the names like "pf0" for Host PCI physical
function representor on Bluefield SmartNIC hosts. This patch
provides correct HPF representor recognition over the kernel
versions 5.7 and laters.

The following port naming formats are supported:

  - missing physical port name (no sysfs/netlink key) at all,
    master is assumed

  - decimal digits (for example "12"), representor is
    assumed, the value is the index of attached VF

  - "p" followed by decimal digits, for example "p2", master
    is assumed

  - "pf" followed by PF index, for example "pf0", Host PF
     representor is assumed on SmartNIC systems.

  - "pf" followed by PF index concatenated with "vf" followed by
     VF index, for example "pf0vf1", representor is assumed.
     If index of VF is "-1" it is a special case of Host PF
     representor, this representor must be indexed in devargs
     as 65535, for example representor=[0-3,65535] will
     allow representors for VF0, VF1, VF2, VF3 and for host PF.

Fixes: 79aa430721b1 ("common/mlx5: split common file under Linux directory")
Cc: stable@dpdk.org
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>