Add touchscreen info for the BUSH Bush Windows tablet.

It was tested using gslx680_ts_acpi module and on patched kernel
installed on device.

Link: https://github.com/onitake/gsl-firmware/pull/215
Link: https://github.com/systemd/systemd/pull/29268Signed-off-by: Tomasz Swiatek <swiatektomasz99@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>