defconfig: Add CONFIG_DEBUG_INFO for sdx12

Kernel symbol size is very small after removed CONFIG_DEBUG_INFO, so
add it back. This change adds below kernel configs for SDX12 debug
build:
  CONFIG_SLUB_DEBUG
  CONFIG_DEBUG_PREEMPT
  CONFIG_SCHED_DEBUG
  CONFIG_HAVE_DEBUG_KMEMLEAK
  CONFIG_DEBUG_BUGVERBOSE
  CONFIG_CC_HAS_KASAN_GENERIC

Change-Id: I502dd3800252077838063a0a4c25fe92bdac4c48
Signed-off-by: Wu Gao <wugao@codeaurora.org>