[ARM] netwinder: clean up GPIO naming

Netwinder was using gpio_xxx names which could clash with the GPIO
layer.  Add a 'nw_' prefix to ensure that these remain separate.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-footbridge/dma.c b/arch/arm/mach-footbridge/dma.c
index b653e9c..4f35063 100644
--- a/arch/arm/mach-footbridge/dma.c
+++ b/arch/arm/mach-footbridge/dma.c
@@ -12,6 +12,7 @@
  */
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/spinlock.h>
 
 #include <asm/dma.h>
 #include <asm/scatterlist.h>