x86: prepare 64-bit architecture initialization for paravirt

This patch prepares the x86_64 architecture initialization for
paravirt. It requires a memory initialization step, which is done
by implementing 64-bit version for machine_specific_memory_setup,
and putting an ARCH_SETUP hook, for guest-dependent initialization.
This last step is done akin to i386

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/smpboot_64.c b/arch/x86/kernel/smpboot_64.c
index c3f2736..cb73c4d 100644
--- a/arch/x86/kernel/smpboot_64.c
+++ b/arch/x86/kernel/smpboot_64.c
@@ -369,7 +369,7 @@
 
 	unlock_ipi_call_lock();
 
-	setup_secondary_APIC_clock();
+	setup_secondary_clock();
 
 	cpu_idle();
 }
@@ -923,7 +923,7 @@
 	 * Set up local APIC timer on boot CPU.
 	 */
 
-	setup_boot_APIC_clock();
+	setup_boot_clock();
 }
 
 /*