qcacmn: QCA vendor attribute to configure NSS

Defines the attribute in SET(GET)_WIFI_CONFIGURATION to dynamically
configure NSS.

Change-Id: Iae0db4ce3aef82c2c075095fea6c34731b86e40b
CRs-Fixed: 2708940

os_if/linux/qca_vendor.h

@@ -4396,6 +4396,18 @@ enum qca_wlan_vendor_attr_config {
 	 */
 	QCA_WLAN_VENDOR_ATTR_CONFIG_RX_STBC = 69,
 
+	/* 8-bit unsigned value. This attribute is used to dynamically configure
+	 * the number of spatial streams. When configured in the disconnected
+	 * state, the updated configuration will be considered for the
+	 * immediately following connection attempt. If the NSS is updated after
+	 * the connection, the updated NSS value is notified to the peer using
+	 * the Operating Mode Notification/Spatial Multiplexing Power Save
+	 * frame. The updated NSS value after the connection shall not be
+	 * greater than the one negotiated during the connection. Any such
+	 * higher value configuration shall be returned with a failure.
+	 */
+	QCA_WLAN_VENDOR_ATTR_CONFIG_NSS = 70,
+
 	/* keep last */
 	QCA_WLAN_VENDOR_ATTR_CONFIG_AFTER_LAST,
 	QCA_WLAN_VENDOR_ATTR_CONFIG_MAX =