soc: renesas: Add r8a7793 SYSC PM Domain Binding Definitions

R-Car M2-N is identical to R-Car M2-W w.r.t. power domains, so reuse the
definitions from the latter.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>