The Espressobin Ultra DTS includes Espressobin DTSI which defines
ethernet-switch@1 node.  The Ultra DTS overrides "reg" to 3, but that
leaves still old unit address which conflicts with the new phy@1 node
(W=1 dtc warning):

  armada-3720-espressobin.dtsi:148.29-203.4: Warning (unique_unit_address_if_enabled): /soc/internal-regs@d0000000/mdio@32004/ethernet-switch@1: duplicate unit-address (also used in node /soc/internal-regs@d0000000/mdio@32004/ethernet-phy@1)

Fix this by deleting ethernet-switch@1 node and merging original node
with code from Ultra DTS into new ethernet-switch@3.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>