altoslib: Move temp GPS API from cal_data to data_listener

altoslib: Move temp GPS API from cal_data to data_listener

This makes the API more consistent, and means that the listener is
responsible for mangaing the temp gps state. In particular, the
AltosDataListener set_gps API now calls the cal_data function.

Signed-off-by: Keith Packard <keithp@keithp.com>