NFC: pn533: Send ATR_REQ only if NFC_PROTO_NFC_DEP bit is set

Currently it is not possible to only poll for passive targets
with the pn533 driver. To change this ATR_REQ is only sent when
NFC_PROTO_NFC_DEP is explicitly requested in poll_protocols.
As most implementations (e.g. neard) poll for all protocols
that are reported to be supported by the adapter, this should
not have much of an effect on current implementations.

Signed-off-by: Michael Thalmeier <michael.thalmeier@hale.at>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>