libutils: include what you use

These includes are included transitively by liblog, but not by the VNDK
version of liblog.

Bug: 33241851
Test: links with BOARD_VNDK_VERSION := current
Change-Id: Ide4aee3cacad2a2bf6bd0cbdf0254c6c245f4020
diff --git a/libutils/misc.cpp b/libutils/misc.cpp
index 2608a65..ab72fe6 100644
--- a/libutils/misc.cpp
+++ b/libutils/misc.cpp
@@ -16,15 +16,11 @@
 
 #define LOG_TAG "misc"
 
-//
-// Miscellaneous utility functions.
-//
 #include <utils/misc.h>
+
+#include <pthread.h>
+
 #include <utils/Log.h>
-
-#if !defined(_WIN32)
-#endif
-
 #include <utils/Vector.h>
 
 using namespace android;