pinctrl: mxs: Make PINCTRL_MXS select PINMUX && PINCONF

Then we can remove "select PINMUX && PINCONF" from PINCTRL_IMX{23,28}.
This simplifies the dependency.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/Kconfig

@@ -100,17 +100,15 @@ config PINCTRL_MMP2
 
 config PINCTRL_MXS
 	bool
+	select PINMUX
+	select PINCONF
 
 config PINCTRL_IMX23
 	bool
-	select PINMUX
-	select PINCONF
 	select PINCTRL_MXS
 
 config PINCTRL_IMX28
 	bool
-	select PINMUX
-	select PINCONF
 	select PINCTRL_MXS
 
 config PINCTRL_NOMADIK