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/bmc/test/firmware_writemeta_unittest.cpp b/bmc/test/firmware_writemeta_unittest.cpp
index 491d669..cb1c965 100644
--- a/bmc/test/firmware_writemeta_unittest.cpp
+++ b/bmc/test/firmware_writemeta_unittest.cpp
@@ -24,8 +24,7 @@
     EXPECT_CALL(imageMock, open("asdf")).WillOnce(Return(true));
 
     EXPECT_TRUE(handler->open(
-        0, blobs::OpenFlags::write | FirmwareBlobHandler::UpdateFlags::ipmi,
-        "asdf"));
+        0, blobs::OpenFlags::write | FirmwareFlags::UpdateFlags::ipmi, "asdf"));
 
     std::vector<std::uint8_t> bytes = {0xaa, 0x55};
 
@@ -38,8 +37,7 @@
     EXPECT_CALL(imageMock, open("asdf")).WillOnce(Return(true));
 
     EXPECT_TRUE(handler->open(
-        0, blobs::OpenFlags::write | FirmwareBlobHandler::UpdateFlags::lpc,
-        "asdf"));
+        0, blobs::OpenFlags::write | FirmwareFlags::UpdateFlags::lpc, "asdf"));
 
     std::vector<std::uint8_t> bytes = {0x01, 0x02, 0x03, 0x04};