tpm: Add extern "C" declaration for C++ compatibility.

The mount-encrypted utility, which includes tlcl.h is in the process
of being converted to C++. To simplify inclusion in C++ code, add the
standard extern "C" linkage specifiers.

BRANCH=none
BUG=chromium:808303
TEST=compiles

Change-Id: I8a99a0e5cfcce64b27cad10735b08ba40434b222
Reviewed-on: https://chromium-review.googlesource.com/915345
Commit-Ready: Mattias Nissler <mnissler@chromium.org>
Tested-by: Mattias Nissler <mnissler@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-by: Andrey Pronin <apronin@chromium.org>
1 file changed