tools: remove phosphor-ipmi-blobs dependency

The host tool depended on the BMC header: firmware_handler.hpp because
it defined the flags.  This header depends on phosphor-ipmi-blobs,
therefore the host-tool depends on this.  Move the flags into a separate
common header file and snip this dependency.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Id2ad33a1611c02605a1ed5c695429d0451eb98d4
diff --git a/tools/p2a.cpp b/tools/p2a.cpp
index 9e246ae..66fc62e 100644
--- a/tools/p2a.cpp
+++ b/tools/p2a.cpp
@@ -16,12 +16,15 @@
 
 #include "p2a.hpp"
 
-#include "firmware_handler.hpp"
+#include "data.hpp"
+#include "flags.hpp"
 #include "pci.hpp"
-#include "pci_handler.hpp"
 
+#include <cstdint>
 #include <cstring>
 #include <ipmiblob/blob_errors.hpp>
+#include <memory>
+#include <string>
 
 namespace host_tool
 {