When one generated .pb.h file includes another generated .pb.h file,
the build can fail because compilation may start before all headers
are generated.
The nanopb_generated_headers target collects all proto generation
targets as dependencies, but the calling target was not depending on
it. This can cause a race condition where the compiler fails with
"No such file or directory" for included headers.
Make the calling target depend on nanopb_generated_headers to ensure
all protobuf headers are generated before source compilation begins.
Signed-off-by: Nick Brook <nrbrook@gmail.com>
c6ba1a067c