PCI/sysfs: Convert "vpd" to static attribute

The "vpd" sysfs attribute allows access to Vital Product Data (VPD).
Previously it was dynamically created either by pci_bus_add_device() or the
pci_sysfs_init() initcall, but since it doesn't need to be created or
removed dynamically, we can use a static attribute so the device model
takes care of addition and removal automatically.

Convert "vpd" to a static attribute and use the .is_bin_visible() callback
to check whether the device supports VPD.

Remove pcie_vpd_create_sysfs_dev_files(),
pcie_vpd_remove_sysfs_dev_files(), pci_create_capabilities_sysfs(), and
pci_create_capabilities_sysfs(), which are no longer needed.

[bhelgaas: This is substantially the same as the earlier patch from Heiner
Kallweit <hkallweit1@gmail.com>.  I included Krzysztof's change here so all
the "convert to static attribute" changes are together.]

[bhelgaas: rename to vpd_read()/vpd_write() and pci_dev_vpd_attr_group]
Suggested-by: Oliver O'Halloran <oohall@gmail.com>
Based-on: https://lore.kernel.org/r/7703024f-8882-9eec-a122-599871728a89@gmail.com


Based-on-patch-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/20210416205856.3234481-5-kw@linux.com


Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>