pwm: stm32: Remove unused struct device

dev is never assigned or used. Remove it.

Fixes: 7edf7369205b ("pwm: Add driver for STM32 plaftorm")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-stm32.c

@@ -20,7 +20,6 @@
 
 struct stm32_pwm {
 	struct pwm_chip chip;
-	struct device *dev;
 	struct clk *clk;
 	struct regmap *regmap;
 	u32 max_arr;