build: add option --enable-host-bios

Add option to enable building in support for the host bios.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I324fc071f07cd364fd39c7df1ccfd9f0fd509a46
diff --git a/util.hpp b/util.hpp
index b791995..8a386e1 100644
--- a/util.hpp
+++ b/util.hpp
@@ -5,6 +5,7 @@
 namespace ipmi_flash
 {
 
+extern const std::string biosBlobId;
 extern const std::string updateBlobId;
 extern const std::string verifyBlobId;
 extern const std::string hashBlobId;