x86: consolidate the definition of the force_mwait variable

The force_mwait variable iss defined either in
arch/x86/kernel/cpu/amd.c or in arch/x86/kernel/setup_64.c, but it is
only initialized and used in arch/x86/kernel/process.c. This patch
moves the declaration to arch/x86/kernel/process.c.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: michael@free-electrons.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 4d629c6..74f2d19 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -15,6 +15,7 @@
 EXPORT_SYMBOL(idle_nomwait);
 
 struct kmem_cache *task_xstate_cachep;
+static int force_mwait __cpuinitdata;
 
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {