gpio: add missing includes in machine.h

linux/types.h and linux/list.h should be included so the typed used in
the header file are always properly declared.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/gpio/machine.h

@@ -1,6 +1,9 @@
 #ifndef __LINUX_GPIO_MACHINE_H
 #define __LINUX_GPIO_MACHINE_H
 
+#include <linux/types.h>
+#include <linux/list.h>
+
 enum gpio_lookup_flags {
 	GPIO_ACTIVE_HIGH = (0 << 0),
 	GPIO_ACTIVE_LOW = (1 << 0),