media: renesas: ceu: Convert to RUNTIME_PM_OPS()

Convert the Renesas Capture Engine Unit driver from SET_RUNTIME_PM_OPS()
to RUNTIME_PM_OPS() and pm_ptr().  This lets us drop the __maybe_unused
annotations from its runtime suspend and resume callbacks, and reduces
kernel size in case CONFIG_PM is disabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>