ipmi: pull the netfn and command into parameters

Pull the netfn and cmd into parameters instead of hard-coding them for
blob commands.

Tested: Only ran unit-tests.
Change-Id: I1a73de32e14cc78ece94a26f6c447824af88c984
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/src/ipmiblob/blob_handler.hpp b/src/ipmiblob/blob_handler.hpp
index 68708d8..c57b11d 100644
--- a/src/ipmiblob/blob_handler.hpp
+++ b/src/ipmiblob/blob_handler.hpp
@@ -130,4 +130,7 @@
     std::unique_ptr<IpmiInterface> ipmi;
 };
 
+constexpr int ipmiOEMNetFn = 46;
+constexpr int ipmiOEMBlobCmd = 128;
+
 } // namespace ipmiblob