Remove pthread_mutex_lock_timeout_np from <pthread.h>.

It's been deprecated long enough, and nothing left in the tree (except
code that isn't even built) is still using it.

Bug: http://b/27918161
Change-Id: I1786f5e2528a23c17b3f7298f4ba5fc7761a26c5
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index fd8aa00..c16126b 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -287,8 +287,6 @@
 // Bionic additions that are deprecated even in the 32-bit ABI.
 int pthread_cond_timedwait_relative_np(pthread_cond_t*, pthread_mutex_t*, const struct timespec*) __attribute__((deprecated("use pthread_cond_timedwait instead")));
 
-int pthread_mutex_lock_timeout_np(pthread_mutex_t*, unsigned) __attribute__((deprecated("use pthread_mutex_timedlock instead")));
-
 #endif /* !defined(__LP64__) */
 
 __END_DECLS