crypto: artpec6 - return correct error code for failed setkey()

->setkey() is supposed to retun -EINVAL for invalid key lengths, not -1.

Fixes: a21eb94f ("crypto: axis - add ARTPEC-6/7 crypto accelerator driver")
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Lars Persson <lars.persson@axis.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Lars Persson <lars.persson@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>