dt-bindings: firmware: qcom,scm: document IPQ5018 compatible

It seems that IPQ5018 compatible was never documented in the bindings.

Signed-off-by: Robert Marko <robimarko@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230816164641.3371878-3-robimarko@gmail.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>