kvm tools: Enable SMP support

kvm tools: Enable SMP support

This patch enables SMP support:

[    0.155072] Brought up 3 CPUs
[    0.155074] Total of 3 processors activated (15158.58 BogoMIPS).

virtio-console was being loaded no matter the cmdline options
and it was causing some hangs (have to look into that).

I'll send this patch to a larger audience once someone
else can confirm it actually works/doesn't work.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>