pwm: mediatek: Initialize clks when the hardware is enabled at probe time

pwm: mediatek: Initialize clks when the hardware is enabled at probe time

When a PWM is already configured by the bootloader (e.g. to power a
backlight), the clk enable count must be increased to keep clock usage
balanced. So check which PWMs are enabled during probe and enable the
respective clocks.

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/20250725154506.2610172-14-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>