platform/x86: silead_dmi: Add DMI match for the I.T.Works TW701 tablet

The I.T.Works TW701 7" tablet is a differently branded version of the
same generic 7" Windows tablet as the Trekstor ST70416-6. Add a DMI
match-table entry for it pointing to the Trekstor's touchscreen info.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>