r8152: fix the poor throughput for 2.5G devices

[ Upstream commit 61b0ad6f ]

Fix the poor throughput for 2.5G devices, when changing the speed from
auto mode to force mode. This patch is used to notify the MAC when the
mode is changed.

Fixes: 195aae32 ("r8152: support new chips")
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>