Make PLDM an optional feature for host dump offload

Host dumps are dumps which created and stored in the host
but offloaded through BMC.
With this change if the host dump needs to de downloaded
the transport mechanism also needs to be provided
    --with-host-dump-offload-transport=<transport>
for eg:
    --with-host-dump-offload-transport=pldm
If no options provided the phosphor-dump-manager will be built
with no host dump offload support and an exception will be thrown
if someone tried to call the host dump offload function.

Signed-off-by: Dhruvaraj Subhashchandran <dhruvaraj@in.ibm.com>
Change-Id: I27311427d8ca8b06b9f33ff5f42bdc7ca87fdcd1
diff --git a/system_dump_entry.cpp b/system_dump_entry.cpp
index 970be7d..53d8788 100644
--- a/system_dump_entry.cpp
+++ b/system_dump_entry.cpp
@@ -1,6 +1,6 @@
 #include "system_dump_entry.hpp"
 
-#include "pldm_interface.hpp"
+#include "offload-extensions.hpp"
 
 namespace phosphor
 {
@@ -8,12 +8,11 @@
 {
 namespace system
 {
-using namespace phosphor::dump::pldm;
 
 void Entry::initiateOffload(std::string uri)
 {
     phosphor::dump::Entry::initiateOffload(uri);
-    requestOffload(sourceDumpId());
+    phosphor::dump::host::requestOffload(sourceDumpId());
 }
 
 } // namespace system