udev-script: udev rule for pci_iomul device.

This patch adds udev rule for pci_iomul device to
create /dev/xen/pci_iomul.

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff --git a/tools/hotplug/Linux/xen-backend.rules b/tools/hotplug/Linux/xen-backend.rules
--- a/tools/hotplug/Linux/xen-backend.rules
+++ b/tools/hotplug/Linux/xen-backend.rules
@@ -6,3 +6,4 @@ SUBSYSTEM=="xen-backend", KERNEL=="vscsi
 SUBSYSTEM=="xen-backend", ACTION=="remove", RUN+="/etc/xen/scripts/xen-hotplug-cleanup"
 KERNEL=="evtchn", NAME="xen/%k"
 KERNEL=="blktap[0-9]*", NAME="xen/%k"
+KERNEL=="pci_iomul", NAME="xen/%k"