ethtool: Add transceiver module extended state

Add an extended state and sub-state to describe link issues related to
transceiver modules.

The 'ETHTOOL_LINK_EXT_SUBSTATE_MODULE_CMIS_NOT_READY' extended sub-state
tells user space that port is unable to gain a carrier because the CMIS
Module State Machine did not reach the ModuleReady (Fully Operational)
state. For example, if the module is stuck at ModuleLowPwr or
ModuleFault state. In case of the latter, user space can read the fault
reason from the module's EEPROM and potentially reset it.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>