s390/pci: Stop usurping pdev->dev.groups

s390/pci: Stop usurping pdev->dev.groups

Bjorn suggests using pdev->dev.groups for attribute_groups constructed on
PCI device enumeration:

  "Is it feasible to build an attribute group in pci_doe_init() and
   add it to dev->groups so device_add() will automatically add them?"
   https://lore.kernel.org/r/20231019165829.GA1381099@bhelgaas

Unfortunately on s390, pcibios_device_add() usurps pdev->dev.groups for
arch-specific attribute_groups, preventing its use for anything else.

Introduce an ARCH_PCI_DEV_GROUPS macro which arches can define in
<asm/pci.h>.  The macro is visible in drivers/pci/pci-sysfs.c through the
inclusion of <linux/pci.h>, which in turn includes <asm/pci.h>.

On s390, define the macro to the three attribute_groups previously assigned
to pdev->dev.groups.  Thereby pdev->dev.groups is made available for use by
the PCI core.

As a side effect, arch/s390/pci/pci_sysfs.c no longer needs to be compiled
into the kernel if CONFIG_SYSFS=n.

Link: https://lore.kernel.org/r/7b970f7923e373d1b23784721208f93418720485.1722870934.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>