pldmtool: Use a non-listening transport for command access

pldmtool does not really need to create a listening (bind) transport
to do a simple send/receive transaction. Hence refactor PldmTransport
allowing a user to specify if the required transport is expected
to be listening or non-listening and switch pldmtool to use a
non-listening transport.

Change-Id: I390298397d71c0ea27234880b844898c7a100ca5
Signed-off-by: Amithash Prasad <amithash@meta.com>
diff --git a/common/transport.hpp b/common/transport.hpp
index e9e1808..c7a1ec0 100644
--- a/common/transport.hpp
+++ b/common/transport.hpp
@@ -19,7 +19,7 @@
 class PldmTransport
 {
   public:
-    PldmTransport();
+    PldmTransport(bool listening = true);
     PldmTransport(const PldmTransport& other) = delete;
     PldmTransport(const PldmTransport&& other) = delete;
     PldmTransport& operator=(const PldmTransport& other) = delete;