net: ethernet: mtk-star-emac: separate tx/rx handling with two NAPIs

[ Upstream commit 0a8bd81f ]

Current driver may lost tx interrupts under bidirectional test with iperf3,
which leads to some unexpected issues.

This patch let rx/tx interrupt enable/disable separately, and rx/tx are
handled in different NAPIs.

Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: Yinghua Pan <ot_yinghua.pan@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: e54b4db3 ("net: ethernet: mtk-star-emac: rearm interrupts in rx_poll only when advised")
Signed-off-by: Sasha Levin <sashal@kernel.org>