Old Mellanox silicons, like switchx-2, switch-ib do not support reading
QSFP modules temperature through MTMP register. Attempt to access this
register on systems equipped with the this kind of silicon will cause
initialization flow failure.
Test for hardware resource capability is added in order to distinct
between old and new silicon - old silicons do not have such capability.

Fixes: 6a79507c ("mlxsw: core: Extend thermal module with per QSFP module thermal zones")
Fixes: 5c42eaa0 ("mlxsw: core: Extend hwmon interface with QSFP module temperature attributes")
Reported-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>