Update NEWS (platform changes section) with MIPS/Android

As of r13767, Valgrind supports MIPS32/Android.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13779 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/NEWS b/NEWS
index 9441c0a..a1e54a4 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@
 
 * ================== PLATFORM CHANGES =================
 
+* Support for Android on MIPS32.
 
 * ==================== TOOL CHANGES ====================