PCI: Move ATS implementation into own file

ATS does not depend on IOV support, so move the code into
its own file. This file will also include support for the
PRI and PASID capabilities later.
Also give ATS its own Kconfig variable to allow selecting it
without IOV support.

Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

include/linux/pci-ats.h

@@ -1,6 +1,8 @@
 #ifndef LINUX_PCI_ATS_H
 #define LINUX_PCI_ATS_H
 
+#include <linux/pci.h>
+
 /* Address Translation Service */
 struct pci_ats {
 	int pos;        /* capability position */