libarchive: fix zstd compression support

The commit 833a452e9 introduced a change that detached
the zstd compression (not decompression) support from base build.

Reported by: kevans
Approved by: re (delphij)

(cherry picked from commit 7f815d4f128f063c1bac361c8f26b52ab7df1e6c)
(cherry picked from commit 3caf7dd45d08a5b7b7fafe39e7aae7d7f8d1a684)