defconfig: Enable preemptirq tracing for msm8998 and sdm660

Enable preemptirq events to trace irqs/preempt disabled callers,
which help to debug scheduler latency sensitive issues (ex: audio
glitches).

Change-Id: I0894b99ee7279cbb5b20639137e0a9b0caa1b0a9
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>