[sonic-platform-common] Update submodule (#1915)

jleveque · lguohan · commit 9e2ceb7cba6b · 2018-08-10T21:56:15.000-07:00
diff --git a/src/sonic-platform-common b/src/sonic-platform-common
@@ -1 +1 @@
-Subproject commit d98600e8ed8df0280cb07487132e20adc48d7f6e
+Subproject commit 664d6cc37b1404ce076bf1addb62e55f93240258
