ledflasher: Remove handler for base.identify command

Since libweave no longer has the 'base' trait, its 'reboot' and
'identify' commands are removed too.

Delete the command handler for 'base.identify' or else ledflasher just
crashes at startup (with 'unknown command' error).

Change-Id: I7d2a19640c53dd288620c0e6dabae389f26dbc11