PCI/sysfs: Move declarations to linux/pci.h

A couple of architectures build the __weak versions of
pci_create_resource_files() and pci_remove_resource_files() but don't
have prototypes for these, which causes warnings:

  drivers/pci/pci-sysfs.c:1253:12: error: no previous prototype for 'pci_create_resource_files' [-Werror=missing-prototypes]
   1253 | int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
  drivers/pci/pci-sysfs.c:1254:13: error: no previous prototype for 'pci_remove_resource_files' [-Werror=missing-prototypes]
   1254 | void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }

Move the prototypes from alpha architecture into the global header to avoid
these warnings for all of them.

Link: https://lore.kernel.org/r/20230810141947.1236730-5-arnd@kernel.org


Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>