defconfig: sdm855: Enable trace & debug features

Enable the IRQSOFF and PREEMPT tracers to help debug
irq and preemption latency problems. Also, enable the
debug options to panic on RT throttling as well as
other scheduler bugs.

Change-Id: Ie54f3d8f90c400a8c32244c4e000ed32e9f15cb1
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>