Change the get_status command to get_clock. Don't report the shutdown
status in the new get_clock command.
The primary purpose of this change is to force the host code to report
a firmware version mismatch with older firmwares as recent changes
(namely the ordering of message block acks) have subtle
incompatibilities if different host/mcu code is used.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>