PCI: Convert ioapic to be builtin only, not modular

Convert pci/ioapic.c to be builtin only, with no module option, so we can
support IO-APIC hotplug.  Also make it depend on X86_IO_APIC.

[bhelgaas: changelog]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

drivers/pci/Kconfig

@@ -105,9 +105,10 @@ config PCI_PASID
 	  If unsure, say N.
 
 config PCI_IOAPIC
-	tristate "PCI IO-APIC hotplug support" if X86
+	bool "PCI IO-APIC hotplug support" if X86
 	depends on PCI
 	depends on ACPI
+	depends on X86_IO_APIC
 	default !X86
 
 config PCI_LABEL

drivers/pci/ioapic.c

@@ -113,6 +113,10 @@ static struct pci_driver ioapic_driver = {
 	.remove		= ioapic_remove,
 };
 
-module_pci_driver(ioapic_driver);
+static int __init ioapic_init(void)
+{
+	return pci_register_driver(&ioapic_driver);
+}
+module_init(ioapic_init);
 
 MODULE_LICENSE("GPL");