ARM: at91: add pinctrl support

This is also include the gpio controller as the IP share both.
Each soc will have to describe the SoC limitation and pin configuration via
DT.

This will allow to do not need to touch the C code when adding new SoC if the
IP version is supported.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 431c375..3d7f11f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -329,6 +329,8 @@
 	select IRQ_DOMAIN
 	select NEED_MACH_GPIO_H
 	select NEED_MACH_IO_H if PCCARD
+	select PINCTRL
+	select PINCTRL_AT91 if USE_OF
 	help
 	  This enables support for systems based on Atmel
 	  AT91RM9200 and AT91SAM9* processors.