support alternative vf representor device naming provided by systemd

[jtluka]

For better deterministics of vf/vf_representor device names, systemd added an option for kernel, see redhat-plumbers/systemd-rhel9@ac7fc3f

The expected naming then is:

PF=enp65s0f0np0
VF=enp65s0f0np0v0
REP=enp65s0f0np0r0

instead of:

PF=enp65s0f0np0 # phys_port_name for PF interface is 'p0'
VF=enp65s0f0np0v0 # v0 is appended for VF0 in case of NAMING_SR_IOV_V
REP=enp65s0f0np0pf0vf0 # phys_port_name for VF0 representor is 'pf0vf0'

We should check if the current code in #346 works fine with this naming scheme. If not we should update the code to cope with the naming scheme.