lib/cbmem: remove cbmem_region_used()

The cbmem_region_used() function wasn't being utilized outside this
module. Threfore, reduce the surface area.

Change-Id: I28a9d02221048ab0aa4cd3d986d17ee7692ce636
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/20858
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/lib/imd_cbmem.c b/src/lib/imd_cbmem.c
index dc17f05..4fb78ce 100644
--- a/src/lib/imd_cbmem.c
+++ b/src/lib/imd_cbmem.c
@@ -266,20 +266,13 @@
 	return imd_entry_at(imd, cbmem_to_imd(entry));
 }
 
-void cbmem_region_used(uintptr_t *base, size_t *size)
-{
-	void *baseptr;
-	imd_region_used(cbmem_get_imd(), &baseptr, size);
-	*base = (uintptr_t)baseptr;
-}
-
 void cbmem_add_bootmem(void)
 {
-	uintptr_t base = 0;
+	void *baseptr = NULL;
 	size_t size = 0;
 
-	cbmem_region_used(&base, &size);
-	bootmem_add_range(base, size, LB_MEM_TABLE);
+	imd_region_used(cbmem_get_imd(), &baseptr, &size);
+	bootmem_add_range((uintptr_t)baseptr, size, LB_MEM_TABLE);
 }
 
 #if ENV_RAMSTAGE || (IS_ENABLED(CONFIG_EARLY_CBMEM_LIST) \