gpio: pca953x: Add regmap dependency for PCA953x driver

Select REGMAP_I2C in Kconfig, since the driver now depends on regmap
and this was missing, thus breaking build on various systems.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -850,6 +850,7 @@ config GPIO_MC9S08DZ60
 
 config GPIO_PCA953X
 	tristate "PCA95[357]x, PCA9698, TCA64xx, and MAX7310 I/O ports"
+	select REGMAP_I2C
 	help
 	  Say yes here to provide access to several register-oriented
 	  SMBus I/O expanders, made mostly by NXP or TI.  Compatible