ARM: at91: always USE_OF from now on

As we always use Device Tree now, we can add the configuration here.
Also remove the condition for PINCTRL_AT91.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 89c4b5c..28f3205 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -376,7 +376,8 @@
 	select IRQ_DOMAIN
 	select NEED_MACH_IO_H if PCCARD
 	select PINCTRL
-	select PINCTRL_AT91 if USE_OF
+	select PINCTRL_AT91
+	select USE_OF
 	help
 	  This enables support for systems based on Atmel
 	  AT91RM9200 and AT91SAM9* processors.