platform/x86: silead_dmi: Add entry for the Teclast X98 Plus II

Add touchscreen platform data for the Teclast X98 Plus II tablet.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>