manager: add getBlobManager as an exported method

getBlobManager will allow a library to get ahold of the BlobManager for
registration purposes.

Change-Id: I75f41601d10d59293c7752da8307507cc2c88434
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/blobs-ipmid/manager.hpp b/blobs-ipmid/manager.hpp
index 8220e0e..14c8b98 100644
--- a/blobs-ipmid/manager.hpp
+++ b/blobs-ipmid/manager.hpp
@@ -250,4 +250,12 @@
     /* Mapping of open blobIds */
     std::unordered_map<std::string, int> openFiles;
 };
+
+/**
+ * @brief Gets a handle to the BlobManager.
+ *
+ * @return a pointer to the BlobManager instance.
+ */
+BlobManager* getBlobManager();
+
 } // namespace blobs