nb/intel/ironlake/raminit.c: initialize 'reply.command'

This to silent a bug found using gcc-10.
src/northbridge/intel/ironlake/raminit.c: In function 'setup_heci_uma':
src/northbridge/intel/ironlake/raminit.c:1805:11: error: 'reply.command' may be used uninitialized in this function [-Werror=maybe-uninitialized]
 1805 |  if (reply.command != (MKHI_SET_UMA | (1 << 7)))
      |      ~~~~~^~~~~~~~
cc1: all warnings being treated as errors

Change-Id: I0d13de549b6d428ac3675ee3f91eb5e42aeb25e8
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42461
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/northbridge/intel/ironlake/raminit.c

@@ -1782,6 +1782,10 @@ static void send_heci_uma_message(struct raminfo *info)
 		u8 field2;
 		u8 unk3[0x48 - 4 - 1];
 	} __packed reply;
+
+	/* FIXME: recv_heci_message() does not always initialize 'reply' */
+	reply.command = 0;
+
 	struct uma_message {
 		u8 group_id;
 		u8 cmd;