qcacld-3.0: Remove legacy STBC config remnants

Change I8cd30439d7ac3de7b550aa5042353cf30e04cbda ("qcacld-3.0:
Refactor MLME CFG items and APIs for VHT") relocated the definitions
of gEnableRXSTBC and gEnableTXSTBC to the MLME component. However this
change left behind in HDD the documentation and CFG macros for these
items, so remove these remnants.

Change-Id: I22eb72e454fa1f9dcb2c6013c28b5148009ff0d9
CRs-Fixed: 2367382

core/hdd/inc/wlan_hdd_cfg.h

@@ -1636,52 +1636,6 @@ enum hdd_link_speed_rpt_type {
 #define HDD_MULTICAST_FILTER_LIST                              0x04
 #define HDD_MULTICAST_FILTER_LIST_CLEAR                        0x05
 
-/*
- * <ini>
- * gEnableRXSTBC - Enables/disables Rx STBC capability in STA mode
- * @Min: 0
- * @Max: 1
- * @Default: 1
- *
- * This ini is used to set default Rx STBC capability
- *
- * Related: None
- *
- * Supported Feature: STA
- *
- * Usage: Internal/External
- *
- * </ini>
- */
-
-#define CFG_ENABLE_RX_STBC                       "gEnableRXSTBC"
-#define CFG_ENABLE_RX_STBC_MIN                   (0)
-#define CFG_ENABLE_RX_STBC_MAX                   (1)
-#define CFG_ENABLE_RX_STBC_DEFAULT               (1)
-
-/*
- * <ini>
- * gEnableTXSTBC - Enables/disables Tx STBC capability in STA mode
- * @Min: 0
- * @Max: 1
- * @Default: 0
- *
- * This ini is used to set default Tx STBC capability
- *
- * Related: None
- *
- * Supported Feature: STA
- *
- * Usage: Internal/External
- *
- * </ini>
- */
-
-#define CFG_ENABLE_TX_STBC                       "gEnableTXSTBC"
-#define CFG_ENABLE_TX_STBC_MIN                   (0)
-#define CFG_ENABLE_TX_STBC_MAX                   (1)
-#define CFG_ENABLE_TX_STBC_DEFAULT               (0)
-
 /*
  * <ini>
  * gEnableSNRMonitoring - Enables SNR Monitoring