NFC: digital: Use NFC_NFCID3_MAXSIZE from nfc.h

This removes the declaration of NFCID3 size in digital_dep.c and now
uses the one from nfc.h.

This also removes a faulty and unneeded call to max().

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>