Spectrum-{1,2,3,4} devices report that a D3hot->D0 transition causes a
reset (i.e., they advertise NoSoftRst-). However, this transition does
not have any effect on the device: It continues to be operational and
network ports remain up. Advertising this support makes it seem as if a
PM reset is viable for these devices. Mark it as unavailable to skip it
when testing reset methods.

Before:

 # cat /sys/bus/pci/devices/0000\:03\:00.0/reset_method
 pm bus

After:

 # cat /sys/bus/pci/devices/0000\:03\:00.0/reset_method
 bus
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>