Add a dts file for tablets using the generic inet-q972 PCB.

Tablets with this PCB feature a mini-hdmi output, micro-usb usb-host,
micro-usb usb-otg, 3.5mm headphone jack, a micro sd slot,
(mini) power-barrel and an usb wifi module.

This has been tested on a 9.7" 1024x768 qware qw tb9718-qhd tablet.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>