syncriscv: add role for mirroring the RISC-V port

Going to be served by all our Geo boxes under riscv.mirror.pkgbuild.com.

group_vars/all/geo.yml

@@ -8,6 +8,3 @@ geo_options:
     health_check_path: /lastupdate
   riscv.mirror.pkgbuild.com:
     health_check_path: /.status/lastupdate.txt
-    # TODO: remove this once we get a cert for asia.mirror.pkgbuild.com
-    # (the original deployment hit a Let's Encrypt duplicate cert limit)
-    hosts: "{{ groups['geo_mirrors'] | difference(['asia.mirror.pkgbuild.com']) }}"