In order to prevent "mlxsw_minimal" driver accessing ASIC during in
service firmware upgrade flow, SDK will raise "OFFLINE" 'udev' event
at early beginning of such flow. When this event is received,
hw-managemnet will remove "mlxsw_minimal" driver.
There is no need to implement opposite "ONLINE" event, since this flow
is ended up with "kexec".
Signed-off-by: Kebo Liu <kebol@nvidia.com>
