sysinfo: Allow showing model info from sysinfo

Some boards may want to show the SKU ID or other information obtained at
runtime. Allow this to come from sysinfo. The board can then provide a
sysinfo driver to provide it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

include/sysinfo.h

@@ -37,9 +37,13 @@ struct udevice;
 enum sysinfo_id {
 	SYSINFO_ID_NONE,
 
+	/* For SMBIOS tables */
 	SYSINFO_ID_SMBIOS_SYSTEM_VERSION,
 	SYSINFO_ID_SMBIOS_BASEBOARD_VERSION,
 
+	/* For show_board_info() */
+	SYSINFO_ID_BOARD_MODEL,
+
 	/* First value available for downstream/board used */
 	SYSINFO_ID_USER = 0x1000,
 };