CBMEM: Clarify CBMEM_TOP_BACKUP function usage

The deprecated LATE_CBMEM_INIT function is renamed:
  set_top_of_ram -> set_late_cbmem_top

Obscure term top_of_ram is replaced:
  backup_top_of_ram -> backup_top_of_low_cacheable
  get_top_of_ram -> restore_top_of_low_cacheable

New function that always resolves to CBMEM top boundary, with
or without SMM, is named restore_cbmem_top().

Change-Id: I61d20f94840ad61e9fd55976e5aa8c27040b8fb7
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/19377
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
diff --git a/src/northbridge/intel/e7505/northbridge.c b/src/northbridge/intel/e7505/northbridge.c
index 71b19f6..f6e14d6 100644
--- a/src/northbridge/intel/e7505/northbridge.c
+++ b/src/northbridge/intel/e7505/northbridge.c
@@ -92,7 +92,7 @@
 				(remaplimitk + 64*1024) - remapbasek);
 		}
 
-		set_top_of_ram(tolmk * 1024);
+		set_late_cbmem_top(tolmk * 1024);
 	}
 	assign_resources(dev->link_list);
 }