pinctrl/at91: remove duplicated include from pinctrl-at91.c

Remove duplicated include.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-at91.c

@@ -20,7 +20,6 @@
 #include <linux/irqdomain.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
-#include <linux/irqdomain.h>
 #include <linux/pinctrl/machine.h>
 #include <linux/pinctrl/pinconf.h>
 #include <linux/pinctrl/pinctrl.h>