defconfig: 8994: enable CONFIG_DEBUG_SLUB_PANIC_ON

This will induce a panic if slab debug catches any
corruptions.

The intention here is to induce collection of data
immediately after the corruption is detected with
the goal to catch the possible source of the corruption.

Change-Id: Id06166cc81488d34a99389092254e324b5803c6b
Signed-off-by: David Keitel <dkeitel@codeaurora.org>