* [plugins]add fan functions, add voltage, current, power for psu
* [plugins]link fanutil.py and psuutil.py to those in 2700
* [plugin]add thermal
* [plugin]add symbol links for thermalutil for all SKUs
Snmp container needs to access the PSU path, but /bsp doesn't mount
into the container, so need to use the real path rather than a symlink.
Signed-off-by: Kevin Wang <kevinw@mellanox.com>
