defconfig: kona: Add MEMCG configurations

Add MEMCG; a required configuration for Android in recent
kernel version.

Change-Id: I4ddd9520a0fc90e03624be7345553170bc131597
Signed-off-by: Jignesh Mehta <jigneshm@codeaurora.org>
Signed-off-by: David Ng <dave@codeaurora.org>
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>