Underscores should not be used in node names (dtc with W=2 warns about
them), so replace them with hyphens.

Cc: Marc Gonzalez <mgonzalez@freebox.fr>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240213143217.336341-1-krzysztof.kozlowski@linaro.orgReviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>