iwlwifi: wake from runtime suspend before sending sync commands

If a host command was queued while in runtime suspend, it would go out
before the D0I3_END_CMD was sent.  Sometimes it works, but sometimes
it fails, and it is obviously the wrong thing to do.

To fix this, have the opmode take a reference before sending a SYNC
command and make the pcie trans wait for the runtime state to become
active before actually queueing the command.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>