spl_nor: fix warning when compiled for 64bit target

Fix "warning: cast to pointer from integer of different size".

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/common/spl/spl_nor.c b/common/spl/spl_nor.c
index e08afe2..d0bd0b0 100644
--- a/common/spl/spl_nor.c
+++ b/common/spl/spl_nor.c
@@ -59,7 +59,7 @@
 	spl_parse_image_header(
 			(const struct image_header *)CONFIG_SYS_UBOOT_BASE);
 
-	memcpy((void *)spl_image.load_addr,
+	memcpy((void *)(unsigned long)spl_image.load_addr,
 	       (void *)(CONFIG_SYS_UBOOT_BASE + sizeof(struct image_header)),
 	       spl_image.size);