Documentation/ABI: Add missed attribute for mlxreg-io sysfs interfaces

Documentation/ABI: Add missed attribute for mlxreg-io sysfs interfaces

BugLink: https://bugs.launchpad.net/bugs/1862227
commit f3efc406d67e6236b513c4302133b0c9be74fd99 upstream.

Add missed "cpld4_version" attribute.

Fixes: 52675da1d087 ("Documentation/ABI: Add new attribute for mlxreg-io sysfs interfaces")
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.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>