ARM: dts: msm: Use quiet_therm thermistors for skin mitigation for SDM450

SDM450 with PMI632 platform doesn't have case_therm thermistor.
Instead use quiet_therm thermistor for skin thermal mitigation
for this platform with old thermal threshold configs based
on recommendation.

Update pop-mem-step trip value to 95C also.

Change-Id: Iba2767387f6f2c6a1cd37d555c5f498e2e39686a
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>