iwlwifi: fw: stop and start debugging using host command

In new devices, access to periphery is forbidden. Send instead
host command to start and stop debugging.

Memory allocation is written in context info, but in case we
need to update it there is a dedicated command. Add definitions,
currently unused, of the new command.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>