x86: Replace ARCH_SETUP by a proper x86_init_ops

ARCH_SETUP is a horrible leftover from the old arch/i386 mach support
code. It still has a lonely user in xen. Move it to x86_init_ops.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 50b20c6..73c7b1d 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -841,7 +841,6 @@
 	.patch = xen_patch,
 
 	.banner = xen_banner,
-	.arch_setup = xen_arch_setup,
 	.post_allocator_init = xen_post_allocator_init,
 };
 
@@ -982,6 +981,7 @@
 	pv_mmu_ops = xen_mmu_ops;
 
 	x86_init.resources.memory_setup = xen_memory_setup;
+	x86_init.oem.arch_setup = xen_arch_setup;
 
 #ifdef CONFIG_X86_64
 	/*