PCI/PTM: Reorder functions in logical order

pci_enable_ptm() and pci_disable_ptm() were separated.
pci_save_ptm_state() and pci_restore_ptm_state() dangled at the top.  Move
them to logical places.  No functional change intended.

Link: https://lore.kernel.org/r/20220909202505.314195-8-helgaas@kernel.org


Tested-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>