m68k: coldfire: Include the GPIO driver header

The Coldfire GPIO driver needs to explicitly incldue the
GPIO driver header since it is providing a driver.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

arch/m68k/coldfire/gpio.c

@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/device.h>
+#include <linux/gpio/driver.h>
 
 #include <linux/io.h>
 #include <asm/coldfire.h>