Handle getTokenData command missing

[puddly]

Some versions of EmberZNet do not include the command at all, even if it is defined in the EZSP version.

home-assistant/core#95632

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (cb3d4f8) 99.77% compared to head (052ddf9) 99.77%.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev     #571   +/-   ##
=======================================
  Coverage   99.77%   99.77%           
=======================================
  Files          67       67           
  Lines        4836     4837    +1     
=======================================
+ Hits         4825     4826    +1     
  Misses         11       11           

Impacted Files	Coverage Δ
bellows/exception.py	100.00% <100.00%> (ø)
bellows/ezsp/__init__.py	99.30% <100.00%> (-0.01%)	⬇️
bellows/ezsp/protocol.py	97.29% <100.00%> (ø)

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[puddly]

Tested with HUSBZB-1, SkyConnect running EZSP v7.1.3.0 and v7.3.3.0, and RCP v7.3.3.0.