iwlwifi: trans: divide stop_hw into stop_device/op_mode_leave

iwlwifi: trans: divide stop_hw into stop_device/op_mode_leave

The stop_hw trans callback is not well defined. It is missing in many
cleanup flows and the division of labor between stop_device/stop_hw
is cumbersome. Remove stop_hw and use stop_device to perform both.
Implement this for all current transports.

PCIE needs some extra configuration the op-mode is leaving to configure
RF kill. Expose this explicitly as a new op_mode_leave trans callback.
Take the call to stop_device outside iwl_run_mvm_init_ucode, this
makes more sense and WARN when we want to run the INIT firmware while
it has run already.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>