Does Ben need this patch in CIP?
Renesas ported a lot of features back for the iwg20m board to the CIP tree. They have an strong interest to run the -rt spin on the CIP kernel too. I don't think Ben needs it but he also prefers the patch flow via the stable tree.
That said, I don't mind adding the patch only to my cip-rt tree if that's the correct way for -rt specific fixes.