arm64: defconfig: add virtio support for running as a kvm guest
arm64: defconfig: add virtio support for running as a kvm guest

When running as a kvm guest on a para-virtualised platform, it is useful
to have virtio implementations of console, 9pfs and network.

This adds these options to the arm64 defconfig, so we can easily run a
defconfig kernel build as both host and as a kvm guest.

Signed-off-by: Will Deacon <b913f13ef92ac157955c954ccaaff7be065faba4@arm.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs