dt-bindings: firmware: scm: Add compatible for SDX65

Add devicetree compatible for SCM present in SDX65 platform.

Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1654080312-5408-5-git-send-email-quic_rohiagar@quicinc.com