defconfig: bengal: update memory configurations

Enable following memory configurations.
debug defconfig:
CMA_DEBUG
ION_POOL_AUTO_REFILL
IOMMU_TLBSYNC_DEBUG
SLUB_DEBUG_PANIC_ON
DEBUG_PANIC_ON_OOM
CONFIG_STACK_HASH_ORDER_SHIFT=20

perf defconfig:
ION_POOL_AUTO_REFILL.

Change-Id: I7cf042d543138f8dc8753c915569bded353a21a3
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>