PM / devfreq: rockchip-dfi: Pass private data struct to internal functions

PM / devfreq: rockchip-dfi: Pass private data struct to internal functions

The internal functions do not need the struct devfreq_event_dev *,
so pass them the struct rockchip_dfi *. This is a preparation for
adding perf support later which doesn't have a struct devfreq_event_dev *.

Link: https://lore.kernel.org/all/20231018061714.3553817-14-s.hauer@pengutronix.de/
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>