mt76: fix monitor rx FCS error in DFS channel

When setup monitor mode in DFS channel, mt76 send CH_SWITCH_DFS to
fw for channel config. This would cause rx performance bad while
monitoring frames. Settings CH_SWITCH_NORMAL in monitor mode would
get the same performance as normal channels.
Reviewed-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/mcu.c

@@ -2151,7 +2151,8 @@ int mt7615_mcu_set_chan_info(struct mt7615_phy *phy, int cmd)
 		.center_chan2 = ieee80211_frequency_to_channel(freq2),
 	};
 
-	if (cmd == MCU_EXT_CMD(SET_RX_PATH))
+	if (cmd == MCU_EXT_CMD(SET_RX_PATH) ||
+	    dev->mt76.hw->conf.flags & IEEE80211_CONF_MONITOR)
 		req.switch_reason = CH_SWITCH_NORMAL;
 	else if (phy->mt76->hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
 		req.switch_reason = CH_SWITCH_SCAN_BYPASS_DPD;

drivers/net/wireless/mediatek/mt76/mt7915/mcu.c

@@ -2885,7 +2885,8 @@ int mt7915_mcu_set_chan_info(struct mt7915_phy *phy, int cmd)
 	}
 #endif
 
-	if (cmd == MCU_EXT_CMD(SET_RX_PATH))
+	if (cmd == MCU_EXT_CMD(SET_RX_PATH) ||
+	    dev->mt76.hw->conf.flags & IEEE80211_CONF_MONITOR)
 		req.switch_reason = CH_SWITCH_NORMAL;
 	else if (phy->mt76->hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
 		req.switch_reason = CH_SWITCH_SCAN_BYPASS_DPD;

drivers/net/wireless/mediatek/mt76/mt7921/mcu.c

@@ -863,7 +863,8 @@ int mt7921_mcu_set_chan_info(struct mt7921_phy *phy, int cmd)
 	else
 		req.channel_band = chandef->chan->band;
 
-	if (cmd == MCU_EXT_CMD(SET_RX_PATH))
+	if (cmd == MCU_EXT_CMD(SET_RX_PATH) ||
+	    dev->mt76.hw->conf.flags & IEEE80211_CONF_MONITOR)
 		req.switch_reason = CH_SWITCH_NORMAL;
 	else if (dev->mt76.hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
 		req.switch_reason = CH_SWITCH_SCAN_BYPASS_DPD;