thermal: set emul_temp when thermal-disabled prop is enabled powerhint will re-enable skin-therm-cpu after device reboot, so we need to set emul_temp to prevent triggering CPU throttling for perf PTS test. Bug: 159105102 Test: emul_temp can be set to 25 degC when thermal-disabled property is enabled Change-Id: I074ed2d06ceec7b527ff2ef3c533f65430855c0a Signed-off-by: TeYuan Wang <kamewang@google.com>