pinctrl-sx150x: Convert driver to use regmap API

To allow for future code simplification

Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 3eea739..5f40ad6 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -171,6 +171,7 @@
 	select PINCONF
 	select GENERIC_PINCONF
 	select GPIOLIB_IRQCHIP
+	select REGMAP
 	help
 	  Say yes here to provide support for Semtech SX150x-series I2C
 	  GPIO expanders as pinctrl module.