gpiolib: devres: add missing headers

Add missing headers for drivers/gpiolib/devres.c.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index fceebdc..307464f 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -15,7 +15,9 @@
  */
 
 #include <linux/module.h>
+#include <linux/err.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/device.h>
 #include <linux/gfp.h>