mac80211: fix passing of VHT80 in IBSS mode

The "iw" utility expects the VHT80 to be specified as uppercase "80MHZ",
change the script to reflect that.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

SVN-Revision: 47814

package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh

@@ -524,7 +524,7 @@ mac80211_setup_adhoc_htmode() {
 			[ "$auto_channel" -gt 0 ] && ibss_htmode="HT40+"
 		;;
 		VHT80)
-			ibss_htmode="80Mhz"
+			ibss_htmode="80MHZ"
 		;;
 		NONE|NOHT)
 			ibss_htmode="NOHT"