ice: Hide bus-info in ethtool for PRs in switchdev mode

Disable showing bus-info information for port representors in switchdev
mode. This fixes a bug that caused displaying wrong netdev descriptions in
lshw tool - one port representor displayed PF branding string, and in turn
one PF displayed a "generic" description. The bug occurs when many devices
show the same bus-info in ethtool, which was the case in switchdev mode (PF
and its port representors displayed the same bus-info). The bug occurs only
if a port representor netdev appears before PF netdev in /proc/net/dev.

In the examples below:
ens6fX is PF
ens6fXvY is VF
ethX is port representor
One irrelevant column was removed from output

Before:
$ sudo lshw -c net -businfo
Bus info          Device      Description
=========================================
pci@0000:02:00.0  eth102       Ethernet Controller E810-XXV for SFP
pci@0000:02:00.1  ens6f1       Ethernet Controller E810-XXV for SFP
pci@0000:02:01.0  ens6f0v0     Ethernet Adaptive Virtual Function
pci@0000:02:01.1  ens6f0v1     Ethernet Adaptive Virtual Function
pci@0000:02:01.2  ens6f0v2     Ethernet Adaptive Virtual Function
pci@0000:02:00.0  ens6f0       Ethernet interface

Notice that eth102 and ens6f0 have the same bus-info and their descriptions
are swapped.

After:
$ sudo lshw -c net -businfo
Bus info          Device      Description
=========================================
pci@0000:02:00.0  ens6f0      Ethernet Controller E810-XXV for SFP
pci@0000:02:00.1  ens6f1      Ethernet Controller E810-XXV for SFP
pci@0000:02:01.0  ens6f0v0    Ethernet Adaptive Virtual Function
pci@0000:02:01.1  ens6f0v1    Ethernet Adaptive Virtual Function
pci@0000:02:01.2  ens6f0v2    Ethernet Adaptive Virtual Function

Fixes: 7aae80ce

 ("ice: add port representor ethtool ops and stats")
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Tested-by: Sandeep Penigalapati <sandeep.penigalapati@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>