qcacmn: Add TX completion logic for WCN6450

In the case of WCN6450, WBM HW block is removed in the UMAC.
TX completions come via HTT messages. Add logic to handle
HTT TX completion messages from the firmware.

Changes are specific to WCN6450 and hence implement the logic
in the arch specific code.

Change-Id: I447020354ce26e8948e4b49648c434fb2ed302cd
CRs-Fixed: 3381814

dp/wifi3.0/dp_tx.h

@@ -624,6 +624,10 @@ uint32_t dp_tx_comp_handler(struct dp_intr *int_ctx, struct dp_soc *soc,
 			    uint32_t quota);
 #endif
 
+void
+dp_tx_comp_process_desc_list(struct dp_soc *soc,
+			     struct dp_tx_desc_s *comp_head, uint8_t ring_id);
+
 QDF_STATUS
 dp_tx_prepare_send_me(struct dp_vdev *vdev, qdf_nbuf_t nbuf);