x86: refactor ->setup_portio_remap() subarch methods

Only NUMAQ has a real ->setup_portio_remap() method, the other
subarchitectures define it but keep it empty.

So mark the vector as NULL, extend the generic code to handle
NULL -setup_portio_remap() entries and remove all the empty
handlers.

Also move the NUMAQ method from the header file into the
 apic driver .c file.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mach-generic/bigsmp.c b/arch/x86/mach-generic/bigsmp.c
index 61396523..4247405 100644
--- a/arch/x86/mach-generic/bigsmp.c
+++ b/arch/x86/mach-generic/bigsmp.c
@@ -84,7 +84,7 @@
 	.cpu_to_logical_apicid		= bigsmp_cpu_to_logical_apicid,
 	.cpu_present_to_apicid		= bigsmp_cpu_present_to_apicid,
 	.apicid_to_cpu_present		= bigsmp_apicid_to_cpu_present,
-	.setup_portio_remap		= setup_portio_remap,
+	.setup_portio_remap		= NULL,
 	.check_phys_apicid_present	= check_phys_apicid_present,
 	.enable_apic_mode		= enable_apic_mode,
 	.phys_pkg_id			= phys_pkg_id,