COMPMID-505: Move PixelWiseMultiplication to new validation

Change-Id: I4daff53f5ee7f0393451425ba20aee1013466954
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/89200
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/utils/TypePrinter.h b/utils/TypePrinter.h
index b072d1a..2fa3d0e 100644
--- a/utils/TypePrinter.h
+++ b/utils/TypePrinter.h
@@ -311,6 +311,13 @@
     return os;
 }
 
+inline std::string to_string(const RoundingPolicy &rounding_policy)
+{
+    std::stringstream str;
+    str << rounding_policy;
+    return str.str();
+}
+
 /** Formatted output of the DataType type. */
 inline ::std::ostream &operator<<(::std::ostream &os, const DataType &data_type)
 {