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/rh/dp_rh_htt.h

@@ -26,6 +26,12 @@
 #include "qdf_mem.h"
 #include "cdp_txrx_cmn_struct.h"
 
+/* sizeof(struct htt_t2h_soft_umac_tx_compl_ind) */
+#define HTT_SOFT_UMAC_TX_COMPL_IND_SIZE	(1 * 4) //in bytes
+
+/* sizeof(struct htt_t2h_tx_msdu_info) */
+#define HTT_TX_MSDU_INFO_SIZE	(8 * 4) //in bytes
+
 /*
  * dp_htt_h2t_rx_ring_rfs_cfg() - RFS config for RX DATA indication
  * @htt_soc: Opaque htt SOC handle