wifi: ath12k: change to treat alpha code na as world wide regdomain

Some firmware versions for WCN7850 report the default regdomain with
alpha code "na" by default when load as a world wide regdomain,
ath12k should treat it as a world wide alpha code.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230906090355.19181-1-quic_wgong@quicinc.com

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

@@ -5421,7 +5421,13 @@ static void ath12k_wmi_htc_tx_complete(struct ath12k_base *ab,
 
 static bool ath12k_reg_is_world_alpha(char *alpha)
 {
-	return alpha[0] == '0' && alpha[1] == '0';
+	if (alpha[0] == '0' && alpha[1] == '0')
+		return true;
+
+	if (alpha[0] == 'n' && alpha[1] == 'a')
+		return true;
+
+	return false;
 }
 
 static int ath12k_reg_chan_list_event(struct ath12k_base *ab, struct sk_buff *skb)