tools: blob add writeMeta to interface

Add the blob write metadata command to the interface.  The LPC interface
will use write meta to configure the BMC's window.

Change-Id: I0266e62174fac428bf0fb84fb9d128451b69e4d8
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/tools/blob_handler.cpp b/tools/blob_handler.cpp
index fd50c00..e1a995d 100644
--- a/tools/blob_handler.cpp
+++ b/tools/blob_handler.cpp
@@ -161,8 +161,9 @@
     }
 }
 
-void BlobHandler::writeBytes(std::uint16_t session, std::uint32_t offset,
-                             const std::vector<std::uint8_t>& bytes)
+void BlobHandler::writeGeneric(BlobOEMCommands command, std::uint16_t session,
+                               std::uint32_t offset,
+                               const std::vector<std::uint8_t>& bytes)
 {
     std::vector<std::uint8_t> payload;
 
@@ -177,7 +178,20 @@
 
     std::copy(bytes.begin(), bytes.end(), std::back_inserter(payload));
 
-    auto resp = sendIpmiPayload(BlobOEMCommands::bmcBlobWrite, payload);
+    auto resp = sendIpmiPayload(command, payload);
+}
+
+void BlobHandler::writeMeta(std::uint16_t session, std::uint32_t offset,
+                            const std::vector<std::uint8_t>& bytes)
+{
+    return writeGeneric(BlobOEMCommands::bmcBlobWriteMeta, session, offset,
+                        bytes);
+}
+
+void BlobHandler::writeBytes(std::uint16_t session, std::uint32_t offset,
+                             const std::vector<std::uint8_t>& bytes)
+{
+    return writeGeneric(BlobOEMCommands::bmcBlobWrite, session, offset, bytes);
 }
 
 std::vector<std::string> BlobHandler::getBlobList()