arm64: dts: r8a7796: Add FCPF and FCPV instances

The FCPs handle the interface between various IP cores and memory. Add
the instances related to the FDPs and VSP2s.

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