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/cpu/intel/smm/gen1/smmrelocate.c

@@ -40,11 +40,6 @@
 #define  G_SMRAME	(1 << 3)
 #define  C_BASE_SEG	((0 << 2) | (1 << 1) | (0 << 0))
 
-struct ied_header {
-	char signature[10];
-	u32 size;
-	u8 reserved[34];
-} __packed;
 
 
 struct smm_relocation_params {