dt-bindings: net: pse-pd: Allow -N suffix for ethernet-pse node names

Extend the pattern matching for PSE-PD controller nodes to allow -N
suffixes. This enables the use of multiple "ethernet-pse" nodes without the
need for a "reg" property.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>