xen: xensyms support

Export Xen symbols to dom0 via /proc/xen/xensyms (similar to
/proc/kallsyms).

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

diff --cc drivers/xen/Kconfig
Simple merge

diff --cc drivers/xen/xenfs/Makefile
Simple merge

diff --cc drivers/xen/xenfs/super.c
Simple merge

diff --cc drivers/xen/xenfs/xenfs.h
Simple merge

diff --cc drivers/xen/xenfs/xensyms.c
Simple merge

diff --cc include/xen/interface/platform.h
Simple merge