While useful, there are advantages for this to be done by the
surrounding code (i.e. fprintd). As such, remove the identify stage from
the goodix driver and rely on fprintd doing it for us.
One can probably argue that neither solution is perfect. Ideally, we
would probably return the information required to delete the old print
to the upper stack and let the driver/device handle the duplicate
checking.
However, for now this works well. We may need to reconsider this if we
get devices that do the duplicate checking transparently and just throw
an enroll error.
Closes: #415
Some OEM will integrate fingerprint device with powerButton. It's
possible that a user may press the power button during fingerprint
enroll or identify. This would lead to unintended PC shutdown or
hibernation. We add pwr_btn_shield cmd and related process to shield
the power button function when the fingerprint functionality (enroll and
identify) is used and restore power button function afterwards.
