[][MAC80211][mt76][Add continuous TX support in testmode tx_frames]

[Description]
Add continuous TX support in testmode tx_frames
Enable continuous TX by setting tx_count=0xFFFFFFFF (UINT_MAX)

[Release-log]
N/A

Change-Id: I9e46fd3c7fabdbb832812d543bf5b6651e848a85
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7267177
diff --git a/feed/atenl/files/iwpriv.sh b/feed/atenl/files/iwpriv.sh
index de74190..6739392 100755
--- a/feed/atenl/files/iwpriv.sh
+++ b/feed/atenl/files/iwpriv.sh
@@ -1180,7 +1180,7 @@
             fi
             param_new=${param}
             if [ "${cmd}" = "ATETXCNT" ] && [ "${param}" = "0" ]; then
-                param_new="10000000"
+                param_new="0xFFFFFFFF"
             fi
             ;;
         "ATETXANT"|"ATERXANT")