x86: fix section mismatch warning in setup_64.c

Fix the following warning:
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x7a3): Section mismatch: reference to .init.text:amd_detect_cmp in 'init_amd'

The function amd_detect_cmp were annotated __init and
was only used from init_amd() which are annotated __cpuinit.

Annotate amd_detect_cmp() with _cpuinit to fix it.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/setup_64.c

@@ -530,7 +530,7 @@ static int nearby_node(int apicid)
  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
  * Assumes number of cores is a power of two.
  */
-static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
+static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
 {
 #ifdef CONFIG_SMP
 	unsigned bits;