meson: enable full subproject build

Misc changes to the build process and adding wrap-files so that
the full repository can be built as a meson subproject.  This
depends on a few pending changes upstream in phosphor-host-ipmid,
but since that subproject references HEAD it will automatically
resolve as those changes are merged.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Idfe21c8d347c513667d7358af0c4a4ddcf3f181b
4 files changed