dt-bindings: net: pse-pd: ti,tps23881: Fix missing "additionalProperties" constraints

The child nodes are missing "additionalProperties" constraints which
means any undocumented properties or child nodes are allowed. Add the
constraints and all the undocumented properties exposed by the fix.

Fixes: f562202f ("dt-bindings: net: pse-pd: Add bindings for TPS23881 PSE controller")
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://lore.kernel.org/r/20240523171750.2837331-1-robh@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>