Move machine type to Q35.

I think it's time, and it'll enable us to add PCIE support.
Later, hopefully we'll be able to do device-passthrough.

I've also took the opportunity to get rid of the video device.
It's not needed.

lago/providers/libvirt/templates/dom_template-base.xml.j2

@@ -7,7 +7,7 @@
       <suspend-to-mem enabled='no'/>
     </pm>
     <os>
-      <type arch='x86_64' machine='pc'>hvm</type>
+      <type arch='x86_64' machine='q35'>hvm</type>
       <bootmenu enable='no'/>
       <bios useserial='no'/>
     </os>
@@ -39,11 +39,6 @@
       <console type='pty'>
         <target type='virtio' port='0'/>
       </console>
-      <video>
-        <model type='cirrus' vram='16384' heads='1'/>
-        <alias name='video0'/>
-        <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
-      </video>
     </devices>
     <clock offset='utc'>
       <timer name='kvmclock'>