arm64: dts: ls1028a-qds-65bb: don't use in-band autoneg for 2500base-x

The Lynx PCS integrated with ENETC port 0 does not support in-band
autoneg for the 2500base-x SERDES protocol, and prints errors from its
phylink methods. Furthermore, the AQR112 card used for these boards does
not expect in-band autoneg either. So delete the extraneous property.

Fixes: e426d63e

 ("arm64: dts: ls1028a-qds: add overlays for various serdes protocols")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>