Always compile in litevm and make sure it won't crash the kernel

litevm is always built in now, it builds and you can boot.

We don't call litevm_init until you attach '#V'. At that point,
if you don't have a working vmxon instruction, you'll get a
panic. This makes #V very useful for crashing all the cores
at once. Unfortunately, once this bug is fixed, you will no longer
have this option for crashing the kernel.

Signed-off-by: Ronald G. Minnich <rminnich@google.com>