arm64: dts: r8a7795: add FDP1 device nodes

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