Enable XZ_DEC_ARM64.

Change-Id: I727a87cde049d2c8372c73e62662e62a8569a9bc
diff --git a/Android.bp b/Android.bp
index 0586a94..f9f46a9 100644
--- a/Android.bp
+++ b/Android.bp
@@ -33,6 +33,7 @@
     cflags: [
         "-DXZ_DEC_X86",
         "-DXZ_DEC_ARM",
+        "-DXZ_DEC_ARM64",
         "-DXZ_DEC_ARMTHUMB",
         "-Wall",
         "-Werror",