dm: exynos: Tidy up GPIO headers

The wrong header is being included, thus requiring the code to re-declare
the generic GPIO interface in each GPIO header.

Fix this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/samsung/smdkc100/smdkc100.c b/board/samsung/smdkc100/smdkc100.c
index e009564..66b6a98 100644
--- a/board/samsung/smdkc100/smdkc100.c
+++ b/board/samsung/smdkc100/smdkc100.c
@@ -7,9 +7,9 @@
  */
 
 #include <common.h>
+#include <asm/gpio.h>
 #include <asm/io.h>
 #include <asm/arch/sromc.h>
-#include <asm/arch/gpio.h>
 #include <netdev.h>
 
 DECLARE_GLOBAL_DATA_PTR;