ppc4xx: Move gpio.h to ppc4xx-gpio.h since its ppc4xx specific

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/amcc/katmai/katmai.c b/board/amcc/katmai/katmai.c
index 15cf703..7301cd5 100644
--- a/board/amcc/katmai/katmai.c
+++ b/board/amcc/katmai/katmai.c
@@ -30,7 +30,7 @@
 #include <netdev.h>
 #include <asm/processor.h>
 #include <asm/io.h>
-#include <asm/gpio.h>
+#include <asm/ppc4xx-gpio.h>
 #include <asm/4xx_pcie.h>
 #include <asm/errno.h>