platform/x86: mlx-platform: Add more definitions for system attributes

Add new attributes for the all type systems specifying for each
equipped CPLD device, the CPLD part number and the CPLD minor version
of the device: 'cpld{n}_pn' and 'cpld{n}_version_min'.
This information is to be used for mathcing the current CPLD image and
for making decision if image upgrade is required for CPLD device.

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>