SNL (Service Name Lookup) allows for LLCP peers to map service names with
SAPs. This is mandatory for connection less support as peers need to get
the right SAPs without sending the CONNECT frame.
Here we only support the Rx part of SNL. The Tx one will be implemented
when supporting connection less LLCP sockets.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>