crypto/ccm: fix auth_data_len upperbound value
crypto/ccm: fix auth_data_len upperbound value

RFC3610 states that len_encoding is only valid for "0x0001 ... 0xFEFF"

   If 0 < l(a) < (2^16 - 2^8), then the length field is encoded as two
   octets which contain the value l(a) in most-significant-byte first
   order.

RIOT-OS/RIOT,jasonatran/RIOT,kYc0o/RIOT,basilfx/RIOT,BytesGalore/RIOT,gebart/RIOT,smlng/RIOT,rfuentess/RIOT,biboc/RIOT,biboc/RIOT,miri64/RIOT,miri64/RIOT,gebart/RIOT,ant9000/RIOT,basilfx/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,aeneby/RIOT,kaspar030/RIOT,lazytech-org/RIOT,authmillenon/RIOT,lazytech-org/RIOT,toonst/RIOT,authmillenon/RIOT,lazytech-org/RIOT,jasonatran/RIOT,yogo1212/RIOT,OlegHahm/RIOT,ant9000/RIOT,mfrey/RIOT,jasonatran/RIOT,OTAkeys/RIOT,basilfx/RIOT,kYc0o/RIOT,miri64/RIOT,BytesGalore/RIOT,cladmi/RIOT,yogo1212/RIOT,ant9000/RIOT,cladmi/RIOT,kYc0o/RIOT,OTAkeys/RIOT,kaspar030/RIOT,miri64/RIOT,rfuentess/RIOT,ant9000/RIOT,BytesGalore/RIOT,yogo1212/RIOT,yogo1212/RIOT,smlng/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,rfuentess/RIOT,cladmi/RIOT,ant9000/RIOT,yogo1212/RIOT,x3ro/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,BytesGalore/RIOT,gebart/RIOT,BytesGalore/RIOT,josephnoir/RIOT,toonst/RIOT,mfrey/RIOT,x3ro/RIOT,x3ro/RIOT,kYc0o/RIOT,mtausig/RIOT,cladmi/RIOT,mtausig/RIOT,mfrey/RIOT,toonst/RIOT,aeneby/RIOT,josephnoir/RIOT,A-Paul/RIOT,lazytech-org/RIOT,x3ro/RIOT,yogo1212/RIOT,mtausig/RIOT,basilfx/RIOT,biboc/RIOT,mfrey/RIOT,smlng/RIOT,rfuentess/RIOT,josephnoir/RIOT,OlegHahm/RIOT,miri64/RIOT,toonst/RIOT,A-Paul/RIOT,basilfx/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,kaspar030/RIOT,cladmi/RIOT,authmillenon/RIOT,mtausig/RIOT,toonst/RIOT,aeneby/RIOT,smlng/RIOT,gebart/RIOT,smlng/RIOT,A-Paul/RIOT,A-Paul/RIOT,OTAkeys/RIOT,A-Paul/RIOT,mfrey/RIOT,aeneby/RIOT,kYc0o/RIOT,authmillenon/RIOT,biboc/RIOT,jasonatran/RIOT,OlegHahm/RIOT,lazytech-org/RIOT,mtausig/RIOT,biboc/RIOT,gebart/RIOT,josephnoir/RIOT,x3ro/RIOT,aeneby/RIOT,kaspar030/RIOT,jasonatran/RIOT,rfuentess/RIOT