[Submodule update] sonic-util

Make sure db_migrator is run after all config are loaded during (#926)
Vnet alias mapping (#924)
Changes to make lldp show command for multi-npu platforms. (#914)
[Mellanox] Fix thermal control issue: use natural sort for fan
status and thermal status (#836)
[Mellanox] add document for thermal control related cli (#832)

Author: abdosi