ARM/PCI: Move to generic PCI domains

Most if not all ARM PCI host controller device drivers either ignore the
domain field in the pci_sys_data structure or just increment it every time
a host controller is probed, using it as a domain counter.

Therefore, instead of relying on pci_sys_data to stash the domain number in
a standard location, ARM pcibios code can be moved to the newly introduced
generic PCI domains code, implemented in commits:

  41e5c0f81d3e ("of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr()")
  670ba0c8883b ("PCI: Add generic domain handling")

ARM code is made to select PCI_DOMAINS_GENERIC by default, which builds
core PCI code that assigns the domain number through the generic function:

  void pci_bus_assign_domain_nr(...)

that relies on a DT property to define the domain number or falls back to a
counter according to a predefined logic; its usage replaces the current
domain assignment code in PCI host controllers present in the kernel.

Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Reviewed-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> # mvebu
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Phil Edworthy <phil.edworthy@renesas.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
CC: Mohit Kumar <mohit.kumar@st.com>
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 1dd7595..1309cfb 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -101,9 +101,7 @@
 	struct mvebu_pcie_port *ports;
 	struct msi_controller *msi;
 	struct resource io;
-	char io_name[30];
 	struct resource realio;
-	char mem_name[30];
 	struct resource mem;
 	struct resource busn;
 	int nports;
@@ -723,18 +721,9 @@
 {
 	struct mvebu_pcie *pcie = sys_to_pcie(sys);
 	int i;
-	int domain = 0;
 
-#ifdef CONFIG_PCI_DOMAINS
-	domain = sys->domain;
-#endif
-
-	snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x",
-		 domain);
-	pcie->mem.name = pcie->mem_name;
-
-	snprintf(pcie->io_name, sizeof(pcie->io_name), "PCI I/O %04x", domain);
-	pcie->realio.name = pcie->io_name;
+	pcie->mem.name = "PCI MEM";
+	pcie->realio.name = "PCI I/O";
 
 	if (request_resource(&iomem_resource, &pcie->mem))
 		return 0;