virt-host-validate: Fix IOMMU output on aarch64

virt-host-validate: Fix IOMMU output on aarch64

virt-host-validate should print "Checking for device assignment IOMMU
support" for all architectures, not only for Intel / AMD.

This is the output without the patch:
```
[fidencio@dentola libvirt]$ virt-host-validate
  QEMU: comprobando if device /dev/kvm exists                                   : PASA
  QEMU: comprobando if device /dev/kvm is accessible                            : PASA
  QEMU: comprobando if device /dev/vhost-net exists                             : PASA
  QEMU: comprobando if device /dev/net/tun exists                               : PASA
  QEMU: comprobando for cgroup 'cpu' controller support                         : PASA
  QEMU: comprobando for cgroup 'cpuacct' controller support                     : PASA
  QEMU: comprobando for cgroup 'cpuset' controller support                      : PASA
  QEMU: comprobando for cgroup 'memory' controller support                      : PASA
  QEMU: comprobando for cgroup 'devices' controller support                     : ADVERTENCIA (Enable 'devices' in kernel Kconfig file or mount/enable cgroup controller in your system)
  QEMU: comprobando for cgroup 'blkio' controller support                       : PASA
ADVERTENCIA (Unknown if this platform has IOMMU support)
  QEMU: comprobando for secure guest support                                    : ADVERTENCIA (Unknown if this platform has Secure Guest support)

```

This is the output with the patch:
```
[fidencio@dentola libvirt]$ ./build/tools/virt-host-validate
  QEMU: Checking if device /dev/kvm exists                                   : PASS
  QEMU: Checking if device /dev/kvm is accessible                            : PASS
  QEMU: Checking if device /dev/vhost-net exists                             : PASS
  QEMU: Checking if device /dev/net/tun exists                               : PASS
  QEMU: Checking for cgroup 'cpu' controller support                         : PASS
  QEMU: Checking for cgroup 'cpuacct' controller support                     : PASS
  QEMU: Checking for cgroup 'cpuset' controller support                      : PASS
  QEMU: Checking for cgroup 'memory' controller support                      : PASS
  QEMU: Checking for cgroup 'devices' controller support                     : WARN (Enable 'devices' in kernel Kconfig file or mount/enable cgroup controller in your system)
  QEMU: Checking for cgroup 'blkio' controller support                       : PASS
  QEMU: Checking for device assignment IOMMU support                         : WARN (Unknown if this platform has IOMMU support)
  QEMU: Checking for secure guest support                                    : WARN (Unknown if this platform has Secure Guest support)
```

Signed-off-by: Fabiano Fidêncio <fabiano@fidencio.org>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>