wifi: ath12k: avoid redundant code in Rx cookie conversion init

Currently, in the Rx data path cookie conversion initialization procedure,
the primary page table index (ppt_idx) is computed within the secondary
page table iteration. However this is invariant, and hence the ppt_idx
should be calculated outside of the iteration to avoid repeated execution
of the statement.

Found in code review.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.1.1-00188-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
Signed-off-by: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240411102226.4045323-2-quic_periyasa@quicinc.com

drivers/net/wireless/ath/ath12k/dp.c

@@ -1425,10 +1425,11 @@ static int ath12k_dp_cc_desc_init(struct ath12k_base *ab)
 			}
 
 			tx_spt_page = i + pool_id * ATH12K_TX_SPT_PAGES_PER_POOL;
+			ppt_idx = ATH12K_NUM_RX_SPT_PAGES + tx_spt_page;
+
 			dp->spt_info->txbaddr[tx_spt_page] = &tx_descs[0];
 
 			for (j = 0; j < ATH12K_MAX_SPT_ENTRIES; j++) {
-				ppt_idx = ATH12K_NUM_RX_SPT_PAGES + tx_spt_page;
 				tx_descs[j].desc_id = ath12k_dp_cc_cookie_gen(ppt_idx, j);
 				tx_descs[j].pool_id = pool_id;
 				list_add_tail(&tx_descs[j].list,