crypto: talitos - fix max key size for sha384 and sha512

Below commit came with a typo in the CONFIG_ symbol, leading
to a permanently reduced max key size regarless of the driver
capabilities.

Reported-by: Horia Geantă <horia.geanta@nxp.com>
Fixes: b8fbdc2b ("crypto: talitos - reduce max key size for SEC1")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>