pdr: Deprecate is_present()

It's likely the case that this was never meant to be part of the public
ABI and should have been marked static. Deprecate it so we can take such
a course of action.

Change-Id: Id9447159ad261a32842dd4bc80bb5ac8245afa42
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/src/pdr.c b/src/pdr.c
index 5cb72f6..bacdd5d 100644
--- a/src/pdr.c
+++ b/src/pdr.c
@@ -872,7 +872,7 @@
 	}
 }
 
-LIBPLDM_ABI_STABLE
+LIBPLDM_ABI_DEPRECATED
 bool is_present(pldm_entity entity, pldm_entity **entities, size_t num_entities)
 {
 	if (entities == NULL || num_entities == 0) {