ARM: dts: msm: Turn off KPTI for Lahaina

Kernel Page Table Isolation (KPTI) is a software workaround
technique used to mitigate the meltdown security vulnarability.
Since Lahaina hardware is meltdown safe, it can safely turn off
the feature. Hence, turn the KPTI off via its command line option.

Change-Id: Idc469ce6804e53073860c32a2635ca9c8f479fe3