arm64: dts: qcom: sm8150-mtp: Add 8150 compatible string

Add "qcom,sm8150" as one of the platform compatible strings.
This will be later used by cpufreq-dt-platdev to exclude using
cpufreq-dt cpufreq driver.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Link: https://lore.kernel.org/r/20210804133223.2503517-1-thara.gopinath@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>