NFC: pn533: Simplify __pn533_send_frame_async

In all cases (send_cmd_async, send_data_async and send_sync)
pn533_send_async_complete() handles all responses internally,
so there is no need to pass this as a callback.

Cmd context is passed to __pn533_send_frame_async in all the
cases as well. It's already kept in struct pn533 which is
available all the time the device is attached. So we can make
use of it instead.

Therefore, cmd_complete and cmd_complete_arg are no needed any more.

Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>