arm64: Add architectural support for PCI

Use the generic PCI domain and OF functions to provide support for PCI
on arm64.

[bhelgaas: Change comments to use generic PCI, not just PCIe.  Nothing at
this level is PCIe-specific.]
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fd4e81a..bc97147 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -81,7 +81,7 @@
 	def_bool y
 
 config NO_IOPORT_MAP
-	def_bool y
+	def_bool y if !PCI
 
 config STACKTRACE_SUPPORT
 	def_bool y
@@ -156,6 +156,26 @@
 config ARM_AMBA
 	bool
 
+config PCI
+	bool "PCI support"
+	help
+	  This feature enables support for PCI bus system. If you say Y
+	  here, the kernel will include drivers and infrastructure code
+	  to support PCI bus devices.
+
+config PCI_DOMAINS
+	def_bool PCI
+
+config PCI_DOMAINS_GENERIC
+	def_bool PCI
+
+config PCI_SYSCALL
+	def_bool PCI
+
+source "drivers/pci/Kconfig"
+source "drivers/pci/pcie/Kconfig"
+source "drivers/pci/hotplug/Kconfig"
+
 endmenu
 
 menu "Kernel Features"