PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope

PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope

Currently, pci_sysfs_init() and sysfs_initialized compile unconditionally,
even on platforms where static attribute groups handle all resource file
creation.

Place them behind a new HAVE_PCI_SYSFS_INIT macro, especially as the
late_initcall is only needed when:

  - HAVE_PCI_LEGACY is set, to iterate buses and create legacy I/O and
    memory files.

  - Neither HAVE_PCI_MMAP nor ARCH_GENERIC_PCI_MMAP_RESOURCE is set, to
    iterate devices and create resource files via the __weak
    pci_create_resource_files() stub override (this is how the Alpha
    architecture handles this currently).

On most systems both conditions are false and the entire late_initcall
compiles away.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Link: https://patch.msgid.link/20260508043543.217179-11-kwilczynski@kernel.org