Move bionic_macros.h from private to platform.

Test: treehugger
Change-Id: Ie473914f4c8924c7240b3ac22093a9daf42fc948
diff --git a/libc/private/bionic_tls.h b/libc/private/bionic_tls.h
index 9a80140..bb5c67b 100644
--- a/libc/private/bionic_tls.h
+++ b/libc/private/bionic_tls.h
@@ -36,7 +36,7 @@
 
 #include <platform/bionic/tls.h>
 
-#include "bionic_macros.h"
+#include "platform/bionic/macros.h"
 #include "grp_pwd.h"
 
 /** WARNING WARNING WARNING