qemu: implement support for Fibre Channel VMID

qemu: implement support for Fibre Channel VMID

Based on kernel commit messages the interface is

    /sys/class/fc/fc_udev_device/appid_store

where we need to write the following string "$INODE:$APPID".

$INODE is the VM root cgroup inode in hexadecimal and $APPID is user
provided string that will be attached to each FC frame for the VM
within the cgroup identified by inode and has limit 128 bytes.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>