x86, mce: Move debugfs mce dir creating to mce.c

Because more debugfs files under mce dir will be create in mce.c.

ChangeLog:

v5:

- Rebased on x86-tip.git/mce

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/cpu/mcheck/mce-internal.h

@@ -22,6 +22,7 @@ struct mce_bank {
 };
 
 int mce_severity(struct mce *a, int tolerant, char **msg);
+struct dentry *mce_get_debugfs_dir(void);
 
 extern int mce_ser;