pwm: Use -EINVAL for unsupported polarity

Instead of using a mix of -EOPNOTSUPP and -ENOTSUPP, use the more
standard -EINVAL to signal that the specified polarity value was
invalid.
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-crc.c

@@ -64,7 +64,7 @@ static int crc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	}
 
 	if (state->polarity != PWM_POLARITY_NORMAL)
-		return -EOPNOTSUPP;
+		return -EINVAL;
 
 	if (pwm_is_enabled(pwm) && !state->enabled) {
 		err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);

drivers/pwm/pwm-iqs620a.c

@@ -50,7 +50,7 @@ static int iqs620_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	int ret;
 
 	if (state->polarity != PWM_POLARITY_NORMAL)
-		return -ENOTSUPP;
+		return -EINVAL;
 
 	if (state->period < IQS620_PWM_PERIOD_NS)
 		return -EINVAL;

drivers/pwm/pwm-rcar.c

@@ -168,7 +168,7 @@ static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	/* This HW/driver only supports normal polarity */
 	if (state->polarity != PWM_POLARITY_NORMAL)
-		return -ENOTSUPP;
+		return -EINVAL;
 
 	if (!state->enabled) {
 		rcar_pwm_disable(rp);