realtek: dts: fix ethernet-switch node

realtek: dts: fix ethernet-switch node

RTL93xx devices can no longer find the switch node in the DTS.
Commit 4c92254 ("relocate/retype switch node") refactored the
switch node definition to better align with upstream. Sadly
the redefinition for RTL93xx devices failed.

- RTL83xx: use "switch0: ethernet-switch"
- RTL93xx: use "switch0: switch@1b000000"

Follow up commit 8b969f7 ("drop realtek,smi-address property)
changed the dts lookup sequence for mdio initialization. On
RTL93xx devices it cannot find the switchnode via
of_get_child_by_name(dev->of_node->parent, "ethernet-switch")

Fix the switch node type for RTL93xx

Fixes: 8b969f7 ("drop realtek,smi-address property)
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/22557
Signed-off-by: Robert Marko <robimarko@gmail.com>