Create compatibility mount point /proc/xen

configname: CONFIG_XEN_COMPAT_XENFS

Linux Kernel Configuration
└─>Device Drivers
└─>Xen driver support
└─>Create compatibility mount point /proc/xen
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
The old xenstore userspace tools expect to find "xenbus"
under /proc/xen, but "xenbus" is now found at the root of the
xenfs filesystem. Selecting this causes the kernel to create
the compatibility mount point /proc/xen if it is running on
a xen platform.
If in doubt, say yes.