[gn build] Port fbb8929

Author: llvmgnsyncbot

llvm/utils/gn/secondary/lldb/tools/lldb-dap/BUILD.gn

@@ -88,7 +88,9 @@ executable("lldb-dap") {
     "LLDBUtils.cpp",
     "OutputRedirector.cpp",
     "ProgressEvent.cpp",
-    "Protocol.cpp",
+    "Protocol/ProtocolBase.cpp",
+    "Protocol/ProtocolRequests.cpp",
+    "Protocol/ProtocolTypes.cpp",
     "RunInTerminal.cpp",
     "SourceBreakpoint.cpp",
     "Transport.cpp",