Backport thermal control feature from master branch to 201911 branch by cherry-picking commits and manually resolving conflicts.
* New SKU support for MSN3420 Signed-off-by: Shlomi Bitton <shlomibi@mellanox.com> Conflicts: device/mellanox/x86_64-mlnx_msn2700-r0/plugins/sfputil.py * Add CPLD's * Symlink fixes and semantics * Adding new platform at end of lines