Fix iwx wrong ac indexs.

[zxystd]

The indexes into the ac array in the iwx_mac_ctxt_cmd_common are from the 
iwx_ac enum and not the txfs. The current code therefore puts the edca params 
in the wrong indexes of the array, causing wrong priority for data-streams of 
different ACs. This bug is not exists in iwm as its txf number is equal to the 
corresponding ac in the iwx_ac enum.

Index: src/sys/dev/pci/if_iwx.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_iwx.c,v
retrieving revision 1.50
diff -u -p -u -r1.50 if_iwx.c
--- src/sys/dev/pci/if_iwx.c    17 Mar 2021 15:59:27 -0000      1.50
+++ src/sys/dev/pci/if_iwx.c    18 Mar 2021 03:28:04 -0000
@@ -5135,6 +5135,17 @@ iwx_ack_rates(struct iwx_softc *sc, stru
        *ofdm_rates = ofdm;
 }
 
+static uint8_t iwx_mac80211_ac_to_ucode_ac(enum ieee80211_edca_ac ac)
+{
+       static const uint8_t iwx_ac_to_ucode_ac[] = {
+               IWX_AC_VO,
+               IWX_AC_VI,
+               IWX_AC_BE,
+               IWX_AC_BK
+       };
+       return iwx_ac_to_ucode_ac[ac];
+}
+
 void
 iwx_mac_ctxt_cmd_common(struct iwx_softc *sc, struct iwx_node *in,
     struct iwx_mac_ctx_cmd *cmd, uint32_t action)
@@ -5181,12 +5192,13 @@ iwx_mac_ctxt_cmd_common(struct iwx_softc
        for (i = 0; i < EDCA_NUM_AC; i++) {
                struct ieee80211_edca_ac_params *ac = &ic->ic_edca_ac[i];
                int txf = iwx_ac_to_tx_fifo[i];
+               uint8_t ucode_ac = iwx_mac80211_ac_to_ucode_ac(i);
 
-               cmd->ac[txf].cw_min = htole16(IWX_EXP2(ac->ac_ecwmin));
-               cmd->ac[txf].cw_max = htole16(IWX_EXP2(ac->ac_ecwmax));
-               cmd->ac[txf].aifsn = ac->ac_aifsn;
-               cmd->ac[txf].fifos_mask = (1 << txf);
-               cmd->ac[txf].edca_txop = htole16(ac->ac_txoplimit * 32);
+               cmd->ac[ucode_ac].cw_min = htole16(IWX_EXP2(ac->ac_ecwmin));
+               cmd->ac[ucode_ac].cw_max = htole16(IWX_EXP2(ac->ac_ecwmax));
+               cmd->ac[ucode_ac].aifsn = ac->ac_aifsn;
+               cmd->ac[ucode_ac].fifos_mask = (1 << txf);
+               cmd->ac[ucode_ac].edca_txop = htole16(ac->ac_txoplimit * 32);
        }
        if (ni->ni_flags & IEEE80211_NODE_QOS)
                cmd->qos_flags |= htole32(IWX_MAC_QOS_FLG_UPDATE_EDCA);