defconfig: disable memory dump v2 and lar unlock from perf on 8994

Disable memory dump v2 driver and debug lar unlock feature from
perf defconfig so as to not incur memory and power overhead.

Change-Id: I4932a7b072bf51ea2279c5d5b51704c3fbf81db3
Signed-off-by: Pratik Patel <pratikp@codeaurora.org>