pwm: rcar: Use PM Runtime to control module clock

Runtime PM API (pm_runtime_get_sync/pm_runtime_put) should be used
to control module clock instead of clk_prepare_enable and
clk_disable_unprepare.
Signed-off-by: NHien Dang <hien.dang.eb@renesas.com>
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-rcar.c

@@ -134,16 +134,12 @@ static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns,
 
 static int rcar_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
-
-	return clk_prepare_enable(rp->clk);
+	return pm_runtime_get_sync(chip->dev);
 }
 
 static void rcar_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
-
-	clk_disable_unprepare(rp->clk);
+	pm_runtime_put(chip->dev);
 }
 
 static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,