dt-bindings: pinctrl: renesas,rzn1: Change maintainer to Fabrizio Castro

Gareth no longer works for Renesas.

Signed-off-by: Chris Paterson <chris.paterson2@renesas.com>
Acked-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Link: https://lore.kernel.org/r/20230426100802.11860-1-chris.paterson2@renesas.com


Signed-off-by: Rob Herring <robh@kernel.org>