cbmem: Add utility to get memory region occupied by cbmem

Change-Id: I8e57c23565f173afc0f4d450579b8bfb35aeb964
Signed-off-by: Alexandru Gagniuc <alexandrux.gagniuc@intel.com>
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/13363
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/cbmem.h

@@ -109,6 +109,8 @@ int cbmem_recovery(int s3resume);
 void *cbmem_add(u32 id, u64 size);
 /* Find a cbmem entry of a given id. These return NULL on failure. */
 void *cbmem_find(u32 id);
+/* Get location and size of CBMEM region in memory */
+void cbmem_region_used(uintptr_t *base, size_t *size);
 
 /* Indicate to each hook if cbmem is being recovered or not. */
 typedef void (* const cbmem_init_hook_t)(int is_recovery);