[ARM] fix pnx4008

arch/arm/mach-pnx4008/include/mach/gpio.h:214: error: implicit declaration of function 'IO_ADDRESS'

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-pnx4008/gpio.c b/arch/arm/mach-pnx4008/gpio.c
index 015cc21..f219914 100644
--- a/arch/arm/mach-pnx4008/gpio.c
+++ b/arch/arm/mach-pnx4008/gpio.c
@@ -18,6 +18,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/io.h>
+#include <mach/hardware.h>
 #include <mach/platform.h>
 #include <mach/gpio.h>