pwm: mediatek: Rework parameters for clk helper function

pwm: mediatek: Rework parameters for clk helper function

Convert pwm_mediatek_clk_enable() and pwm_mediatek_clk_disable() to take
lower level parameters. This enables these functions to be used in the next
commit when there is no valid pwm_chip and pwm_device yet.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250725154506.2610172-13-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>