host/gap: fix doxygen for ble_gap_ext_disc()
Documentation for the parameters `filter_duplicates` and
`filter_policy` for ble_gap_ext_disc() was missing.
@@ -1592,6 +1592,16 @@ int ble_gap_disc(uint8_t own_addr_type, int32_t duration_ms,
* its last Scan Duration until it begins the
* subsequent Scan Duration. Specify 0 to scan
* continuously. Units are 1.28 second.
+ * @param filter_duplicates Set to enable packet filtering in the
+ * controller
+ * @param filter_policy Set the used filter policy. Valid values are:
+ * - BLE_HCI_SCAN_FILT_NO_WL
+ * - BLE_HCI_SCAN_FILT_USE_WL
+ * - BLE_HCI_SCAN_FILT_NO_WL_INITA
+ * - BLE_HCI_SCAN_FILT_USE_WL_INITA
+ * - BLE_HCI_SCAN_FILT_MAX
+ * This parameter is ignored unless
+ * @p filter_duplicates is set.
* @param limited If limited discovery procedure should be used.
* @param uncoded_params Additional arguments specifying the particulars
* of the discovery procedure for uncoded PHY.
