Use struct pn533_cmd instead of pn533_send_async_complete_arg
to track the context of the issued cmd.

This way pn533_send_async_complete_arg struct is no needed
anymore. Just move issuer complete callback to pn533_cmd struct.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>