edac: add a new memory layer type

There are some cases where the memory controller layout is
completely hidden. This is the case of firmware-driven error
code, like the one provided by GHES. Add a new layer to be
used on such memory error report mechanisms.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/linux/edac.h b/include/linux/edac.h
index 4784213..1b7744c 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -375,6 +375,9 @@
  * @EDAC_MC_LAYER_CHANNEL:	memory layer is named "channel"
  * @EDAC_MC_LAYER_SLOT:		memory layer is named "slot"
  * @EDAC_MC_LAYER_CHIP_SELECT:	memory layer is named "chip select"
+ * @EDAC_MC_LAYER_ALL_MEM:	memory layout is unknown. All memory is mapped
+ *				as a single memory area. This is used when
+ *				retrieving errors from a firmware driven driver.
  *
  * This enum is used by the drivers to tell edac_mc_sysfs what name should
  * be used when describing a memory stick location.
@@ -384,6 +387,7 @@
 	EDAC_MC_LAYER_CHANNEL,
 	EDAC_MC_LAYER_SLOT,
 	EDAC_MC_LAYER_CHIP_SELECT,
+	EDAC_MC_LAYER_ALL_MEM,
 };
 
 /**