cbmem: remove cbmem_set_top()

Now that the users of cbmem_set_top() always provide a consistent
cbmem_top() value there's no need to have cbmem_set_top() around.
Therefore, delete it.

Change-Id: I0c96e2b8b829eddbeb1fdf755ed59c51ea689d1b
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/10314
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/include/cbmem.h

@@ -176,9 +176,6 @@ void cbmem_initialize_empty_id_size(u32 id, u64 size);
  * below 4GiB. */
 void *cbmem_top(void);
 
-/* Set the top address for dynamic cbmem. Not for new designs. */
-void cbmem_set_top(void *ramtop);
-
 /* Add a cbmem entry of a given size and id. These return NULL on failure. The
  * add function performs a find first and do not check against the original
  * size. */