pwm: sifive: Consistently name pwm_chip variables "chip"

Most variables holding a pointer to a pwm_chip are called "chip" which
is also the usual name in most other PWM drivers. Rename the single
variable that have a different name to be called "chip", too, for
consistency.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-sifive.c

@@ -51,9 +51,9 @@ struct pwm_sifive_ddata {
 };
 
 static inline
-struct pwm_sifive_ddata *pwm_sifive_chip_to_ddata(struct pwm_chip *c)
+struct pwm_sifive_ddata *pwm_sifive_chip_to_ddata(struct pwm_chip *chip)
 {
-	return container_of(c, struct pwm_sifive_ddata, chip);
+	return container_of(chip, struct pwm_sifive_ddata, chip);
 }
 
 static int pwm_sifive_request(struct pwm_chip *chip, struct pwm_device *pwm)