intel/smm: Define struct ied_header just once

Change-Id: I6fc083aa30d05c11c1b6db7b3facacf5ae857c92
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34855
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/include/cpu/intel/smm_reloc.h

@@ -16,6 +16,12 @@
 
 #include <types.h>
 
+struct ied_header {
+	char signature[10];
+	u32 size;
+	u8 reserved[34];
+} __packed;
+
 /* These helpers are for performing SMM relocation. */
 u32 northbridge_get_tseg_base(void);
 u32 northbridge_get_tseg_size(void);