edac: create top-level debugfs directory

Create a single, top-level "edac" directory for debugfs. An "mc[0-N]"
directory is then created for each memory controller. Individual drivers
can create additional entries such as h/w error injection control.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/edac/edac_module.h

@@ -56,6 +56,20 @@ extern void edac_mc_reset_delay_period(int value);
 
 extern void *edac_align_ptr(void **p, unsigned size, int n_elems);
 
+/*
+ * EDAC debugfs functions
+ */
+#ifdef CONFIG_EDAC_DEBUG
+int edac_debugfs_init(void);
+void edac_debugfs_exit(void);
+#else
+static inline int edac_debugfs_init(void)
+{
+	return -ENODEV;
+}
+static inline void edac_debugfs_exit(void) {}
+#endif
+
 /*
  * EDAC PCI functions
  */