wifi: mt76: mt7921e: fix random fw download fail

In case of PCIe interoperability problem shows up, the firmware
payload may be corrupted in download stage. Turn off L0s to keep
fw download process accurately.

[ 1093.528363] mt7921e 0000:3b:00.0: Message 00000007 (seq 7) timeout
[ 1093.528414] mt7921e 0000:3b:00.0: Failed to start patch
[ 1096.600156] mt7921e 0000:3b:00.0: Message 00000010 (seq 8) timeout
[ 1096.600207] mt7921e 0000:3b:00.0: Failed to release patch semaphore
[ 1097.699031] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1098.758427] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1099.834408] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1100.915264] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1101.990625] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1103.077587] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1104.173258] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1105.248466] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1106.336969] mt7921e 0000:3b:00.0: Timeout for driver own
[ 1106.397542] mt7921e 0000:3b:00.0: hardware init failed

Cc: stable@vger.kernel.org
Fixes: bf3747ae ("mt76: mt7921: enable aspm by default")
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>