PCI/sysfs: Convert "index", "acpi_index", "label" to static attributes

The "label", "index", and "acpi_index" sysfs attributes show firmware label
information about the device.  If the ACPI Device Name _DSM is implemented
for the device, we have:

  label        Device name (optional, may be null)
  acpi_index   Instance number (unique under \_SB scope)

When there is no ACPI _DSM and SMBIOS provides an Onboard Devices structure
for the device, we have:

  label        Reference Designation, e.g., a silkscreen label
  index        Device Type Instance

Previously these attributes were dynamically created either by
pci_bus_add_device() or the pci_sysfs_init() initcall, but since they don'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 "label", "index", and "acpi_index" to static attributes.

Presence of the ACPI _DSM (device_has_acpi_name()) determines whether the
ACPI information (label, acpi_index) or the SMBIOS information (label,
index) is visible.

[bhelgaas: commit log, split to separate patch, add "pci_dev_" prefix]
Suggested-by: Oliver O'Halloran <oohall@gmail.com>
Link: https://lore.kernel.org/r/20210416205856.3234481-6-kw@linux.com


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