Generated files should not be copyright

Because these files are generated, there is no copyright that makes
sense, as these are "derivative works".  sdbusplus does not include
these in its generated files, bmcweb should do the same.

Tested:
Code compiles.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I3c729f8c03176770b31b4f54ebdbdab92daae163