media: v4l: rcar_fdp1: Change platform dependency to ARCH_RENESAS

The Renesas Fine Display Processor driver is used on Renesas R-Car SoCs
only.  Since commit 9b5ba0df

 ("ARM: shmobile: Introduce
ARCH_RENESAS") is ARCH_RENESAS a more appropriate platform dependency
than the legacy ARCH_SHMOBILE, hence use the former.

This will allow to drop ARCH_SHMOBILE on ARM and ARM64 in the near
future.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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>