mlxsw: core: Remove critical trip points from thermal zones

Disable software thermal protection by removing critical trip points
from all thermal zones.

The software thermal protection is redundant given there are two layers
of protection below it in firmware and hardware. The first layer is
performed by firmware, the second, in case firmware was not able to
perform protection, by hardware.
The temperature threshold set for hardware protection is always higher
than for firmware.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>