[clang][interface][storage] Don't define empty structs if using C++

storage_file_read_resp and storage_rpmb_send_resp are both empty struct
definitions but these have different sizes in C(0) and C++(1) which makes
them unsafe to be used across languages.

Change-Id: Ia0e7b4b40c4fb4433f488e97a1082734ade1815f
1 file changed
tree: d616adcd1bf6fe84090ccc0fed6dc365e4f77daf
  1. include/
  2. interface/
  3. lib/