pdr: Make entity_association_tree_find() static

entity_association_tree_find() was deprecated in v0.4.0, mark it static
as it should have been.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: Ie3ee6780eb4a6bc8829fa2e3ab9939f03782c59c
diff --git a/src/pdr.c b/src/pdr.c
index a4c8291..23044a9 100644
--- a/src/pdr.c
+++ b/src/pdr.c
@@ -1164,9 +1164,9 @@
 	return node;
 }
 
-LIBPLDM_ABI_DEPRECATED
-void entity_association_tree_find(pldm_entity_node *node, pldm_entity *entity,
-				  pldm_entity_node **out)
+static void entity_association_tree_find(pldm_entity_node *node,
+					 pldm_entity *entity,
+					 pldm_entity_node **out)
 {
 	if (node == NULL) {
 		return;