rt2800: OFDM rates are mandatory

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ralink/rt2x00/rt2800lib.c

@@ -1707,7 +1707,7 @@ void rt2800_config_erp(struct rt2x00_dev *rt2x00dev, struct rt2x00lib_erp *erp,
 
 	if (changed & BSS_CHANGED_BASIC_RATES) {
 		rt2800_register_write(rt2x00dev, LEGACY_BASIC_RATE,
-					 erp->basic_rates);
+				      0xff0 | erp->basic_rates);
 		rt2800_register_write(rt2x00dev, HT_BASIC_RATE, 0x00008003);
 	}