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/taihu/lcd.c b/board/amcc/taihu/lcd.c
index 9b2afda..15cfcb0 100644
--- a/board/amcc/taihu/lcd.c
+++ b/board/amcc/taihu/lcd.c
@@ -22,7 +22,7 @@
 #include <common.h>
 #include <command.h>
 #include <asm/io.h>
-#include <asm/gpio.h>
+#include <asm/ppc4xx-gpio.h>
 
 #define LCD_CMD_ADDR	0x50100002
 #define LCD_DATA_ADDR	0x50100003