ARM: dts: msm: do not limit Shutdown SoCs

Currently the property qcom,shutdown-soc-valid-limit is set to 20.
This has the effect of limiting the valid range of shutdown state of
charge to be within 20 percent of the calculated power on SoC.

However, there exist certain conditions under high current charging
or discharging that will make the power on SoC deviate a lot from the
real SoC. Thus it is better to always use the shutdown SoC instead
of limiting it to be within 20 percent of the calculated SoC.

Change-Id: I39a25697fd7137e491b34ef7c0e78e0eb804a37b
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>