mt76: mt7615: remove unnecessary register operations

Remove mt76_wr(dev, MT_CSR(0x010), 0x8208) that would cause
MT_PCIE_IRQ_ENABLE to be disabled; MT_PCIE_IRQ_ENABLE should always keep
on enabled when the driver is running.

0x44064 is a not existing address

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>