PCI/ATS: Move pci_prg_resp_pasid_required() to CONFIG_PCI_PRI

pci_prg_resp_pasid_required() returns the value of the "PRG Response PASID
Required" bit from the PRI capability, but the interface was previously
defined under #ifdef CONFIG_PCI_PASID.

Move it from CONFIG_PCI_PASID to CONFIG_PCI_PRI so it's with the other
PRI-related things.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>