arm64: dts: qcom: sm8250: Add fallback CCI compatible

Add a fallback CCI compatible, as required by bindings.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221213183305.544644-4-konrad.dybcio@linaro.org