x86, apic: clean up ->setup_apic_routing()

- separate the namespace

 - remove macros

 - remove namespace clash on 64-bit

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/genapic.h b/arch/x86/include/asm/genapic.h
index 661898c..38b1202 100644
--- a/arch/x86/include/asm/genapic.h
+++ b/arch/x86/include/asm/genapic.h
@@ -107,7 +107,7 @@
 extern struct genapic apic_x2apic_uv_x;
 DECLARE_PER_CPU(int, x2apic_extra_bits);
 
-extern void setup_apic_routing(void);
+extern void default_setup_apic_routing(void);
 #endif
 
 #endif /* _ASM_X86_GENAPIC_64_H */