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_ymodem.c b/common/spl/spl_ymodem.c
index fdd5261..038b443 100644
--- a/common/spl/spl_ymodem.c
+++ b/common/spl/spl_ymodem.c
@@ -96,7 +96,7 @@
 	int ret;
 	connection_info_t info;
 	char buf[BUF_SIZE];
-	struct image_header *ih = NULL;
+	struct legacy_img_hdr *ih = NULL;
 	ulong addr = 0;
 
 	info.mode = xyzModem_ymodem;
@@ -111,9 +111,9 @@
 		goto end_stream;
 
 	if (IS_ENABLED(CONFIG_SPL_LOAD_FIT_FULL) &&
-	    image_get_magic((struct image_header *)buf) == FDT_MAGIC) {
+	    image_get_magic((struct legacy_img_hdr *)buf) == FDT_MAGIC) {
 		addr = CONFIG_SYS_LOAD_ADDR;
-		ih = (struct image_header *)addr;
+		ih = (struct legacy_img_hdr *)addr;
 
 		memcpy((void *)addr, buf, res);
 		size += res;
@@ -129,7 +129,7 @@
 		if (ret)
 			return ret;
 	} else if (IS_ENABLED(CONFIG_SPL_LOAD_FIT) &&
-	    image_get_magic((struct image_header *)buf) == FDT_MAGIC) {
+	    image_get_magic((struct legacy_img_hdr *)buf) == FDT_MAGIC) {
 		struct spl_load_info load;
 		struct ymodem_fit_info info;
 
@@ -147,7 +147,7 @@
 		while ((res = xyzModem_stream_read(buf, BUF_SIZE, &err)) > 0)
 			size += res;
 	} else {
-		ih = (struct image_header *)buf;
+		ih = (struct legacy_img_hdr *)buf;
 		ret = spl_parse_image_header(spl_image, bootdev, ih);
 		if (ret)
 			goto end_stream;
@@ -158,7 +158,7 @@
 #endif
 			addr = spl_image->load_addr;
 		memcpy((void *)addr, buf, res);
-		ih = (struct image_header *)addr;
+		ih = (struct legacy_img_hdr *)addr;
 		size += res;
 		addr += res;
 
@@ -177,7 +177,7 @@
 
 #ifdef CONFIG_SPL_GZIP
 	if (!(IS_ENABLED(CONFIG_SPL_LOAD_FIT) &&
-	      image_get_magic((struct image_header *)buf) == FDT_MAGIC) &&
+	      image_get_magic((struct legacy_img_hdr *)buf) == FDT_MAGIC) &&
 	    (ih->ih_comp == IH_COMP_GZIP)) {
 		if (gunzip((void *)(spl_image->load_addr + sizeof(*ih)),
 			   CONFIG_SYS_BOOTM_LEN,