Add support for Schneider Electric RZ/N1D and RZ/N1S boards, which
are based on the Reneasas RZ/N1 SoC devices.
The intention is to support both boards using a single defconfig, and to
handle the differences at runtime.
Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>