With mt7621 soc_dev_attr fixed to register the soc as a device,
kernel will experience an oops in soc_device_match_attr
This quirk test was introduced in the staging driver in
commit 9445ccb3714c ("staging: mt7621-pci-phy: add quirks for 'E2'
revision using 'soc_device_attribute'"). The staging driver was removed,
and later re-added in commit d87da32372a0 ("phy: ralink: Add PHY driver
for MT7621 PCIe PHY") for kernel 5.11