runner: add --machine-type option

Also, --arch and --machine-type can get "any" as the value, to allow
filtering on one but not the other.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
jeos: prepare for non-Fedora JeOS images

In principle, there is no reason why JeOS images should be Fedora images.
To prepare for that, let the config parser pick any JeOS image that
satisfies --arch and --machine-type requirements.  And move existing
Fedora-specific values to the JeOS.17.64 definition.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu: support NIC with no model

Some architectures do not support using -device to instantiate NICs.
Instead, you use "-net nic,netdev=foo" and the QEMU board code will
define the NICs.  These can be supported by not defining a value
for the nic_model value.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
guest-hw: add a couple more drive types

spapr_vscsi is used by ppc64.  sd is used on ARM and other embedded
architectures.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>