pwm: atmel-tcb: add missing clk source config

Clock source changes are never applied to the CMR register.
This may lead to wrong period/duty cycle configuration.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-atmel-tcb.c

@@ -249,6 +249,8 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 		}
 	}
 
+	cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
+
 	__raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
 
 	if (index == 0)