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>

arch/arm/Kconfig

@@ -376,7 +376,8 @@ config ARCH_AT91
 	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.