iwlwifi: mvm: add some missing command strings

Some command strings in the system group weren't added
for debug, add them now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211204130722.5bbda292908e.I53cefd74547a745fd29261a795c94611e7ee8d1d@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>