crypto: sun4i-ss - Move to Allwinner directory

Since we have a dedicated Allwinner directory for crypto driver, move
the sun4i-ss driver in it.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>