mb/emulation/qemu: Move packed attribute

The jenkins build complains about this now that clang has been added.

src/mainboard/emulation/qemu-q35/cpu.c:37:1: error:
attribute '__packed__' is ignored, place it after "union" to apply
attribute to type declaration [-Werror,-Wignored-attributes]
__packed union save_state {

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Id8faa24239505d808d09c00d825344edc7c4b7d9
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69494
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/mainboard/emulation/qemu-q35/cpu.c

@@ -34,7 +34,7 @@ static void get_smm_info(uintptr_t *perm_smbase, size_t *perm_smsize,
  * SMRAM entry point to here.
  */
 
-__packed union save_state {
+union __packed save_state {
 	amd64_smm_state_save_area_t amd64;
 	struct {
 		char _reserved[sizeof(amd64_smm_state_save_area_t)