build: Make it possible to use as a subproject
build: Make it possible to use as a subproject

We can't pull in nested subprojects with meson, but we can still
leverage it to download the project and use clever symlinking to build.

Change-Id: I54099df45cb5f5757f2ed36d3ca20ba8206e0281
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/google-misc,openbmc/google-misc,openbmc/google-misc