wlan: Start TX sample timer only for SAP flow control

Start TX sample timer only when FW supports the soft AP
TX flow buffer allocation control feature.

Change-Id: I717e33d56ce50a5b40bf7694916639b101aa2e47
CRs-Fixed: 2213536
diff --git a/CORE/TL/src/wlan_qct_tl.c b/CORE/TL/src/wlan_qct_tl.c
index 845a58d..57ddaa9 100644
--- a/CORE/TL/src/wlan_qct_tl.c
+++ b/CORE/TL/src/wlan_qct_tl.c
@@ -843,7 +843,8 @@
   vos_atomic_set_U8( &pTLCb->ucTxSuspended, 0);
   pTLCb->uResCount = uResCount;
 
-  vos_timer_start(&pTLCb->tx_frames_timer, WLANTL_SAMPLE_INTERVAL);
+  if (IS_FEATURE_SUPPORTED_BY_FW(SAP_BUFF_ALLOC))
+    vos_timer_start(&pTLCb->tx_frames_timer, WLANTL_SAMPLE_INTERVAL);
 
   return VOS_STATUS_SUCCESS;
 }/* WLANTL_Start */