dt-bindings: media: renesas-fcp: Remove SoC-specific compatible strings

The FCP IP cores include a version register that identifies which SoC
model the IP is integrated in. SoC-specific compatible strings are not
needed.

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