ARM: dts: qcom: disable skin-temp mitigation for khaje-qrd-pm7250b

The skin-temp thermistor is placed very near to parallel charger SMB
chip on khaje-qrd-pm7250b device and it would throttle charging current
a lot. Disable SW based skin-temp mitigation and rely on the SMB-temp
mitigation for thermal regulation.

Change-Id: Ide7b2b73a79504a3b3a7a4fa6fae82de4c2a1a06