d5af729dc207 ("PCI: Mark NVIDIA T4 GPUs to avoid bus reset") avoided
Secondary Bus Reset on the T4 because the reset seemed to not work when the
T4 was directly attached to a Root Port.
But NVIDIA thinks the issue is probably related to some issue with the Root
Port, not with the T4. The T4 provides neither PM nor FLR reset, so
masking bus reset compromises this device for assignment scenarios.
Revert d5af729dc207 as requested by Wu Zongyong. This will leave SBR
broken in the specific configuration Wu tested, as it was in v6.5, so Wu
will debug that further.