iwlwifi: additional comments in iwl_cfg

No functional changes, just add additional comments to iwl_cfg structure
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

drivers/net/wireless/iwlwifi/iwl-core.h

@@ -278,6 +278,8 @@ struct iwl_mod_params {
  * @chain_noise_calib_by_driver: driver has the capability to perform
  *	chain noise calibration operation
  * @scan_antennas: available antenna for scan operation
+ * @need_dc_calib: need to perform init dc calibration
+ * @bt_statistics: use BT version of statistics notification
  *
  * We enable the driver to be backward compatible wrt API version. The
  * driver specifies which APIs it supports (with @ucode_api_max being the