Fixed MPI assembly for ARM when -O2 is used

GCC with -O2 or higher also needs to now about 'cc' in the clobber list.
(cherry picked from commit eff2e6d4146b72637fbec2ea6b8b800b3f3d9980)

Conflicts:
	ChangeLog
diff --git a/ChangeLog b/ChangeLog
index 50c270f..18be08a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 PolarSSL ChangeLog
 
+= Branch 1.2
+Bugfix
+   * Fix for MPI assembly for ARM
+
 = Version 1.2.6 released 2013-03-11
 Bugfix
    * Fixed memory leak in ssl_free() and ssl_reset() for active session