scons: get protocol info from slicc instead of file parsing

src/mem/ruby/protocol/SConscript

@@ -93,9 +93,8 @@ def slicc_emitter(target, source, env):
 
         # Dynamically determine protocol and add ProtocolInfo.hh to the list of
         # files to be built
-        protocol_name = os.path.splitext(os.path.basename(filepath))[0]
         protocol_file = output_dir.File(
-            f"{protocol_name}/{protocol_name}ProtocolInfo.hh"
+            f"{slicc.protocol}/{slicc.protocol}ProtocolInfo.hh"
         )
         files.update([protocol_file])