pwm: pca9685: depends on I2C rather than REGMAP_I2C

REGMAP_I2C is not a visible config option.
Thus make PWM_PCA9685 depend on I2c and then select REGMAP_I2C.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 5de6fcf..3f66427 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -112,7 +112,8 @@
 
 config PWM_PCA9685
 	tristate "NXP PCA9685 PWM driver"
-	depends on OF && REGMAP_I2C
+	depends on OF && I2C
+	select REGMAP_I2C
 	help
 	  Generic PWM framework driver for NXP PCA9685 LED controller.