x86: zImage: Move subarch assignment out of cmd_line check

The commit

  20bfac0599 ("x86: zImage: add Intel MID platforms support")

introduced an assignment of subarch field in boot parameters, though
missed the right place of doing that. It doesn't matter if we have or
not a kernel command line supplied, we just set that field. Although
guard it by protocol version which supports it.

Fixes: 20bfac0599 ("x86: zImage: add Intel MID platforms support")
Cc: Vincent Tinelli <vincent.tinelli@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/lib/zimage.c

@@ -246,14 +246,15 @@ int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 			hdr->setup_move_size = 0x9100;
 		}
 
-#if defined(CONFIG_INTEL_MID)
-		hdr->hardware_subarch = X86_SUBARCH_INTEL_MID;
-#endif
-
 		/* build command line at COMMAND_LINE_OFFSET */
 		build_command_line(cmd_line, auto_boot);
 	}
 
+#ifdef CONFIG_INTEL_MID
+	if (bootproto >= 0x0207)
+		hdr->hardware_subarch = X86_SUBARCH_INTEL_MID;
+#endif
+
 	setup_video(&setup_base->screen_info);
 
 	return 0;