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/arch/arm/mach-k3/sysfw-loader.c b/arch/arm/mach-k3/sysfw-loader.c
index b3beeca..aea640b 100644
--- a/arch/arm/mach-k3/sysfw-loader.c
+++ b/arch/arm/mach-k3/sysfw-loader.c
@@ -88,10 +88,10 @@
  * Populate SPL hook to override the default load address used by the SPL
  * loader function with a custom address for SYSFW loading.
  */
-struct image_header *spl_get_load_buffer(ssize_t offset, size_t size)
+struct legacy_img_hdr *spl_get_load_buffer(ssize_t offset, size_t size)
 {
 	if (sysfw_loaded)
-		return (struct image_header *)(CONFIG_SYS_TEXT_BASE + offset);
+		return (struct legacy_img_hdr *)(CONFIG_SYS_TEXT_BASE + offset);
 	else if (sysfw_load_address)
 		return sysfw_load_address;
 	else
@@ -490,7 +490,7 @@
 	sysfw_loaded = true;
 
 	/* Ensure the SYSFW image is in FIT format */
-	if (image_get_magic((const image_header_t *)sysfw_load_address) !=
+	if (image_get_magic((const struct legacy_img_hdr *)sysfw_load_address) !=
 	    FDT_MAGIC)
 		panic("SYSFW image not in FIT format!\n");