target/i386: Fix sanity check on max APIC ID / X2APIC enablement

target/i386: Fix sanity check on max APIC ID / X2APIC enablement

The check on x86ms->apic_id_limit in pc_machine_done() had two problems.

Firstly, we need KVM to support the X2APIC API in order to allow IRQ
delivery to APICs >= 255. So we need to call/check kvm_enable_x2apic(),
which was done elsewhere in *some* cases but not all.

Secondly, microvm needs the same check. So move it from pc_machine_done()
to x86_cpus_init() where it will work for both.

The check in kvm_cpu_instance_init() is now redundant and can be dropped.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20220314142544.150555-1-dwmw2@infradead.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>