net: axienet: Properly handle PCS/PMA PHY for 1000BaseX mode

stable inclusion
from stable-5.10.27
commit 3e08fd4a82986f200baa77312b1f248bb567b04e
bugzilla: 51493

--------------------------------

[ Upstream commit 1a025560 ]

Update the axienet driver to properly support the Xilinx PCS/PMA PHY
component which is used for 1000BaseX and SGMII modes, including
properly configuring the auto-negotiation mode of the PHY and reading
the negotiated state from the PHY.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/20201028171429.1699922-1-robert.hancock@calian.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by:   Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>