Amr: Add printing of simulation time

[mirenradia]

Summary

A very small PR to add the printing of simulation time in Amr::timeStep (for Amr::verbose > 0).

Additional background

Though the time is already printed out every coarse timestep here, with deep AMR hierarchies, it can be a long amount of [wall]time between these printouts, hence I would find it useful to see the current simulation time more often

Checklist

The proposed changes:

• fix a bug or incorrect behavior in AMReX
• add new capabilities to AMReX
• changes answers in the test suite to more than roundoff level
• are likely to significantly affect the results of downstream AMReX users
• include documentation in the code and/or rst files, if appropriate