treewide: Drop image_header_t typedef

This is not needed and we should avoid typedefs. Use the struct instead
and rename it to indicate that it really is a legacy struct.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/spl_nor.c b/common/spl/spl_nor.c
index 7986e93..281c613 100644
--- a/common/spl/spl_nor.c
+++ b/common/spl/spl_nor.c
@@ -26,7 +26,7 @@
 static int spl_nor_load_image(struct spl_image_info *spl_image,
 			      struct spl_boot_device *bootdev)
 {
-	__maybe_unused const struct image_header *header;
+	__maybe_unused const struct legacy_img_hdr *header;
 	__maybe_unused struct spl_load_info load;
 
 	/*
@@ -41,7 +41,7 @@
 		 * Load Linux from its location in NOR flash to its defined
 		 * location in SDRAM
 		 */
-		header = (const struct image_header *)CONFIG_SYS_OS_BASE;
+		header = (const struct legacy_img_hdr *)CONFIG_SYS_OS_BASE;
 #ifdef CONFIG_SPL_LOAD_FIT
 		if (image_get_magic(header) == FDT_MAGIC) {
 			int ret;
@@ -72,7 +72,7 @@
 
 			memcpy((void *)spl_image->load_addr,
 			       (void *)(CONFIG_SYS_OS_BASE +
-					sizeof(struct image_header)),
+					sizeof(struct legacy_img_hdr)),
 			       spl_image->size);
 #ifdef CONFIG_SYS_SPL_ARGS_ADDR
 			spl_image->arg = (void *)CONFIG_SYS_SPL_ARGS_ADDR;
@@ -92,7 +92,7 @@
 	 * defined location in SDRAM
 	 */
 #ifdef CONFIG_SPL_LOAD_FIT
-	header = (const struct image_header *)spl_nor_get_uboot_base();
+	header = (const struct legacy_img_hdr *)spl_nor_get_uboot_base();
 	if (image_get_magic(header) == FDT_MAGIC) {
 		debug("Found FIT format U-Boot\n");
 		load.bl_len = 1;