BugLink: https://bugs.launchpad.net/bugs/1883918

commit 7222a1b5 upstream

Add documentation for the SRBDS vulnerability and its mitigation.

 [ bp: Massage.
   jpoimboe: sysfs table strings. ]
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>