input-raw: fix ts_read_mt for non-MT devices without pressure
input-raw: fix ts_read_mt for non-MT devices without pressure

We always use our "multitouch buffer" in read_mt - also for single touch
devices. We cannot check for real MT capabilities when setting the pressure
fallback values.

kergoth/tslib,kergoth/tslib,kergoth/tslib,kergoth/tslib