arm64: dts: r8a77965: add FDP1 device nodes

The r8a77965 has a single FDP1 instance.

Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>