pwm: tiecap: Make use of pwmchip_parent() accessor

struct pwm_chip::dev is about to change. To not have to touch this
driver in the same commit as struct pwm_chip::dev, use the accessor
function provided for exactly this purpose.

Link: https://lore.kernel.org/r/ae92e06b49437ca7e768b1f8b405170e33948a70.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-tiecap.c

@@ -70,7 +70,7 @@ static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		duty_cycles = (u32)c;
 	}
 
-	pm_runtime_get_sync(chip->dev);
+	pm_runtime_get_sync(pwmchip_parent(chip));
 
 	value = readw(pc->mmio_base + ECCTL2);
 
@@ -100,7 +100,7 @@ static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		writew(value, pc->mmio_base + ECCTL2);
 	}
 
-	pm_runtime_put_sync(chip->dev);
+	pm_runtime_put_sync(pwmchip_parent(chip));
 
 	return 0;
 }
@@ -111,7 +111,7 @@ static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
 	u16 value;
 
-	pm_runtime_get_sync(chip->dev);
+	pm_runtime_get_sync(pwmchip_parent(chip));
 
 	value = readw(pc->mmio_base + ECCTL2);
 
@@ -124,7 +124,7 @@ static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	writew(value, pc->mmio_base + ECCTL2);
 
-	pm_runtime_put_sync(chip->dev);
+	pm_runtime_put_sync(pwmchip_parent(chip));
 
 	return 0;
 }
@@ -135,7 +135,7 @@ static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	u16 value;
 
 	/* Leave clock enabled on enabling PWM */
-	pm_runtime_get_sync(chip->dev);
+	pm_runtime_get_sync(pwmchip_parent(chip));
 
 	/*
 	 * Enable 'Free run Time stamp counter mode' to start counter
@@ -162,7 +162,7 @@ static void ecap_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	writew(value, pc->mmio_base + ECCTL2);
 
 	/* Disable clock on PWM disable */
-	pm_runtime_put_sync(chip->dev);
+	pm_runtime_put_sync(pwmchip_parent(chip));
 }
 
 static int ecap_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -275,11 +275,11 @@ static void ecap_pwm_save_context(struct pwm_chip *chip)
 {
 	struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
 
-	pm_runtime_get_sync(chip->dev);
+	pm_runtime_get_sync(pwmchip_parent(chip));
 	pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2);
 	pc->ctx.cap4 = readl(pc->mmio_base + CAP4);
 	pc->ctx.cap3 = readl(pc->mmio_base + CAP3);
-	pm_runtime_put_sync(chip->dev);
+	pm_runtime_put_sync(pwmchip_parent(chip));
 }
 
 static void ecap_pwm_restore_context(struct pwm_chip *chip)