iwlwifi: mvm: set HCMD_NAME for PHY_DB as well

Currently it is logged as UNKNOWN.
Also, 0x6c seems to be the permanent ID for this command, remove
incorrect comment and uncomment the command from the commands
list.

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