package/moarvm: enable on sparc and sparc64

sparc and sparc64 are supported since version 2020.09 and
https://github.com/MoarVM/MoarVM/commit/87ad486f30ecdf28b4abbcf40139467f626f8548
https://github.com/MoarVM/MoarVM/commit/34e0fb55e33482fe09083627eb54003bde07d8a7



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>