arm64: defconfig: Enable haven doorbell driver

Enable doorbell driver for VMs to communicate each other over an IPC

Change-Id: Id72d186ada0a81bcf7b6706834c2110518983d71
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
Signed-off-by: Elliot Berman <eberman@codeaurora.org>