hwdb: explicitly label the XP-PEN STAR 06 as tablet

Exports BTN_LEFT...BTN_FORWARD, BTN_TOUCH, REL_X/Y/WHEEL/MISC and
ABS_X/Y/PRESSURE. Rather than figure out what builtin-input_id tweak we need
for this device, just add the tablet bit.

https://gitlab.freedesktop.org/xorg/driver/xf86-input-libinput/issues/8