qcacmn: Added change to correct Tx PPDU BW value

This change required to match Tx PPDU BW value with
FW stats. As per firmware enums its starts with 5MHz
BW value. So to match 20MHz value with enum zero, need
to subtract from BW populated from TLV.

Change-Id: Ifcc49839c08de78c9200b877890fdce2e0846f1d

dp/wifi3.0/dp_htt.c

@@ -1767,7 +1767,7 @@ static void dp_process_ppdu_stats_user_rate_tlv(struct dp_pdev *pdev,
 	ppdu_user_desc->txbf =
 		HTT_PPDU_STATS_USER_RATE_TLV_TXBF_GET(*tag_buf);
 	ppdu_user_desc->bw =
-		HTT_PPDU_STATS_USER_RATE_TLV_BW_GET(*tag_buf);
+		HTT_PPDU_STATS_USER_RATE_TLV_BW_GET(*tag_buf) - 2;
 	ppdu_user_desc->nss = HTT_PPDU_STATS_USER_RATE_TLV_NSS_GET(*tag_buf);
 	ppdu_user_desc->mcs = HTT_PPDU_STATS_USER_RATE_TLV_MCS_GET(*tag_buf);
 	ppdu_user_desc->preamble =