libbinder: stop exporting private headers

Having a 'private' include directory for a library is somewhat of an
artifact. There is no need to export these (or once include_dirs is
eliminated, make them available at any capacity). We want libbinder to
completely encapsulate the kernel API.

Bug: N/A
Test: binderLibTest
Change-Id: If84ff928a186f3397150660c2cc1faadb46b796c
diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index 6fb1227..ef7fd44 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -29,8 +29,6 @@
 #include <utils/SystemClock.h>
 #include <utils/threads.h>
 
-#include <private/binder/binder_module.h>
-
 #include <atomic>
 #include <errno.h>
 #include <inttypes.h>
@@ -43,6 +41,7 @@
 #include <unistd.h>
 
 #include "Static.h"
+#include "binder_module.h"
 
 #if LOG_NDEBUG