Update pddm to work with clang-format

Add clang-format off/on directives around pddm expansions to simplify formatting other code.
diff --git a/Makefile.am b/Makefile.am
index 079ac70..f4cda52 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -530,6 +530,7 @@
   java/util/src/test/proto/com/google/protobuf/util/json_test.proto
 
 objectivec_EXTRA_DIST=                                                       \
+  objectivec/.clang-format                                                   \
   objectivec/DevTools/check_version_stamps.sh                                \
   objectivec/DevTools/compile_testing_protos.sh                              \
   objectivec/DevTools/full_mac_build.sh                                      \