x86: zImage: add Intel MID platforms support

Intel MID platform boards have special treatment, such as boot parameter
setting.

Assign hardware_subarch accordingly if CONFIG_INTEL_MID is set.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Vincent Tinelli <vincent.tinelli@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

arch/x86/lib/zimage.c

@@ -246,6 +246,10 @@ 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);
 	}