pci: add quirk to disable Function-Level Reset (FLR)

MediaTek mt76 WiFi cards are advertising FLR support but after issuing
a FLR the chipset is gone. Add a quirk so we can disable FLR. The
current reset code will automatically fall back to a power reset.

This makes the card show up under bhyve where before it would just not
be discovered at all. That should make wifibox work for it and will help
development for a LinuxKPI based mt76 driver as found in framework laptops
as no dedicated machine and constant reboots are needed anymore.
We will likely need to add more PCI vendor/device IDs once we can test
the other device IDs.

After a lot of help from: jhb
Really implemented by: jhb (I just typed and tested)
GH issue: github.com/pgj/freebsd-wifibox/issues/73
Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D52728

(cherry picked from commit 4c0e53aced2251eb5ac7eca44e13a6b947be8582)