iwlwifi: fix RFkill while calibrating

If the RFkill interrupt fires while we calibrate, it would
make the firmware fail and the driver wasn't able to recover.
Change the flow so that the driver will kill the firmware
in that case.

Since we have now two flows that are calling
trans_stop_device (the RFkill interrupt and the
op_mode_mvm_start function) - we need to better sync this.
Use the STATUS_DEVICE_ENABLED in the pcie transport in an
atomic way to achieve this.

This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=86231

CC: <stable@vger.kernel.org> [3.10+]
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>