MIPS: Fix the build on jz4740 after removing the custom gpio.h

Somehow the wrong version of the patch to remove the use of custom
gpio.h on mips has been merged. This patch add the missing fixes for a
build error on jz4740 because linux/gpio.h doesn't provide any machine
specfics definitions anymore.

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11089/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/jz4740/gpio.c b/arch/mips/jz4740/gpio.c
index a74e181..8c6d76c 100644
--- a/arch/mips/jz4740/gpio.c
+++ b/arch/mips/jz4740/gpio.c
@@ -28,6 +28,7 @@
 #include <linux/seq_file.h>
 
 #include <asm/mach-jz4740/base.h>
+#include <asm/mach-jz4740/gpio.h>
 
 #define JZ4740_GPIO_BASE_A (32*0)
 #define JZ4740_GPIO_BASE_B (32*1)