powerpc: Introduce ppc_pci_flags accessors

Currently there are a number of platforms that open code access to
the ppc_pci_flags global variable.  However, that variable is not
present if CONFIG_PCI is not set, which can lead to a build break.

This introduces a number of accessor functions that are defined
to be empty in the case of CONFIG_PCI being disabled.  The
various platform files in the kernel are updated to use these.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/powermac/pci.c

@@ -729,7 +729,7 @@ static void __init setup_bandit(struct pci_controller *hose,
 static int __init setup_uninorth(struct pci_controller *hose,
 				 struct resource *addr)
 {
-	ppc_pci_flags |= PPC_PCI_REASSIGN_ALL_BUS;
+	ppc_pci_add_flags(PPC_PCI_REASSIGN_ALL_BUS);
 	has_uninorth = 1;
 	hose->ops = &macrisc_pci_ops;
 	hose->cfg_addr = ioremap(addr->start + 0x800000, 0x1000);
@@ -996,7 +996,7 @@ void __init pmac_pci_init(void)
 	struct device_node *np, *root;
 	struct device_node *ht = NULL;
 
-	ppc_pci_flags = PPC_PCI_CAN_SKIP_ISA_ALIGN;
+	ppc_pci_set_flags(PPC_PCI_CAN_SKIP_ISA_ALIGN);
 
 	root = of_find_node_by_path("/");
 	if (root == NULL) {
@@ -1055,7 +1055,7 @@ void __init pmac_pci_init(void)
 	 * some offset between bus number and domains for now when we
 	 * assign all busses should help for now
 	 */
-	if (ppc_pci_flags & PPC_PCI_REASSIGN_ALL_BUS)
+	if (ppc_pci_has_flag(PPC_PCI_REASSIGN_ALL_BUS))
 		pcibios_assign_bus_offset = 0x10;
 #endif
 }