iwlwifi: mvm: enable sending HE_AIR_SNIFFER command via debugfs

In order to receive TB (Trigger Based) PPDU in monitor mode,
the Driver must send the HE_AIR_SNIFFER_CONFIG_CMD host command.
Enable that via debugfs.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Ido Yariv <idox.yariv@intel.com>
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>