platform/x86: silead_dmi: Add entry for newer BIOS for Trekstor Surftab 7.0

Some versions of the Trekstor Surftab 7.0 ship with a newer BIOS which uses
different DMI strings.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>