hwdb: add resolution override for Pinebook Pro touchpad

The Pinebook Pro touchpad returns a resolution data that is 2 times of
the real value, which makes libinput think the touchpad is only 1/4 the
real size.

Add a resolution override value for it, to allow libinput to calculate
the distance moved on it correctly.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>