alpha/PCI: Make pdev_save_srm_config() static

pdev_save_srm_config() and struct pdev_srm_saved_conf are only used in
arch/alpha/kernel/pci.c, so make them static there.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>