The ethernet doesn't work anymore in both linux-libre and linux-libre-lts with the following error in dmesg:

[   44.990545] cpsw 4a100000.ethernet: initializing cpsw version 1.12 (0)
[   45.021380] cpsw 4a100000.ethernet: phy "/ocp/interconnect@4a000000/segment@0/target-module@100000/ethernet@0/mdio@1000/ethernet-phy@0" not found on slave 0

It looks like a mismatch between the dts and the linux-libre kernels

linux-libre-lts version: 5.4.60-gnu-1-lts

It works again now with linux-libre-lts.

I still have to try with linux-libre.