hw: Nuke hw_compat_4_0_1 and pc_compat_4_0_1

Commit c87759ce fixed a regression affecting pc-q35 machines by
introducing a new pc-q35-4.0.1 machine version to be used instead
of pc-q35-4.0. The only purpose was to revert the default behaviour
of not using split irqchip, but the change also introduced the usual
hw_compat and pc_compat bits, and wired them for pc-q35 only.

This raises questions when it comes to add new compat properties for
4.0* machine versions of any architecture. Where to add them ? In
4.0, 4.0.1 or both ? Error prone. Another possibility would be to teach
all other architectures about 4.0.1. This solution isn't satisfying,
especially since this is a pc-q35 specific issue.

It turns out that the split irqchip default is handled in the machine
option function and doesn't involve compat lists at all.

Drop all the 4.0.1 compat lists and use the 4.0 ones instead in the 4.0.1
machine option function.

Move the compat props that were added to the 4.0.1 since c87759ce to
4.0.

Even if only hw_compat_4_0_1 had an impact on other architectures,
drop pc_compat_4_0_1 as well for consistency.

Fixes: c87759ce "q35: Revert to kernel irqchip"
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <156051774276.244890.8660277280145466396.stgit@bahia.lan>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>