add aarch64 linux and darwin as default platforms

Signed-off-by: Matt Wrock <matt@mattwrock.com>

Author: mwrock

components/builder-api/habitat/default.toml

@@ -1,7 +1,7 @@
 log_level = "info"
 
 [api]
-targets = ["x86_64-linux", "x86_64-linux-kernel2", "x86_64-windows"]
+targets = ["x86_64-linux", "x86_64-linux-kernel2", "x86_64-windows", "aarch64-darwin", "aarch64-linux"]
 saas_bldr_url = "https://bldr.habitat.sh"
 license_server_url = "http://licensing-acceptance.chef.co"
 allowed_native_package_origins = []