zstd: add configure options

legacy_level=0 disables support for packages compressed with zstd before
version 0.8 (~August 2016).

Support for the other compression libraries adds a symlink feature to the
zstd binary for it to mimic that library's regular tool. Example, a
symlink pointing to zstd named 'gzip' will cause zstd to pretend to be gzip.
The cli tools aren't used, so there is no purpose to adding this support.

Signed-off-by: Ian Leonard <antonlacon@gmail.com>

packages/compress/zstd/package.mk

@@ -15,3 +15,9 @@ PKG_TOOLCHAIN="meson"
 configure_package() {
   PKG_MESON_SCRIPT="${PKG_BUILD}/build/meson/meson.build"
 }
+
+PKG_MESON_OPTS_HOST="-Dlegacy_level=0 \
+                     -Dbin_programs=false \
+                     -Dzlib=disabled \
+                     -Dlzma=disabled \
+                     -Dlz4=disabled"