arm64: dts: msm8996: fix PSCI entry-latency-us

The current entry-latency-us is too short.
The proper way to convert between the device tree properties
from the vendor tree to the upstream PSCI device tree properties is:

entry-latency-us = qcom,time-overhead - qcom,latency-us

which gives

entry-latency-us = 210 - 80 = 130

Fixes: f6aee7af ("arm64: dts: qcom: msm8996: Add PSCI cpuidle low power states")
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>