counter: stm32-timer-cnt: Reset TIM_TISEL to its default value in probe

The driver assumes that the input selection register (TIM_TISEL) is at
its reset default value. Usually this is the case, but the bootloader
might have modified it.

This bases on a similar patch submitted by Olivier Moysan for pwm-stm32.
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230413212339.3611722-1-u.kleine-koenig@pengutronix.de/Signed-off-by: William Breathitt Gray <william.gray@linaro.org>

drivers/counter/stm32-timer-cnt.c

@@ -342,6 +342,9 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
+	/* Reset input selector to its default input */
+	regmap_write(priv->regmap, TIM_TISEL, 0x0);
+
 	/* Register Counter device */
 	ret = devm_counter_add(dev, counter);
 	if (ret < 0)