media: v4l: rcar_fdp1: Enable compilation on Gen2 platforms

Commit 1d389714 ("[media] v4l: rcar_fdp1: add FCP dependency") fixed
a compilation breakage when the optional VIDEO_RENESAS_FCP dependency is
compiled as a module while the rcar_fdp1 driver is built in. As a side
effect it disabled compilation on Gen2 by disallowing the valid
combination ARCH_RENESAS && !VIDEO_RENESAS_FCP. Fix it by handling the
dependency the same way the vsp1 driver did in commit 19994673
("[media] vsp1: clarify FCP dependency").

Fixes: 1d389714 ("[media] v4l: rcar_fdp1: add FCP dependency")

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>