defconfig: arm64: Enable sched debug features for kona

To be able to debug performance issues related to scheduler and
other scheduler bugs, enable below debug features:
  1. PREEMPTIRQ_EVENTS
  2. PANIC_ON_SCHED_BUG
  3. PANIC_ON_RT_THROTTLING

Change-Id: I24c6266e9f014fb25c7cb418382f8aa55217c359
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>