nfc: export header for userspace

* We're not actually pn544, but userspace expects pn544.h
* Since the magic is the same between it and pn547, this should
  be fine for now.

Change-Id: I3e1a6b07de78dbd4705116c9cd1656beaedfd387
Merge "nfc: export header for userspace" into cm-12.0