crypto: talitos - enhanced talitos_desc struct for SEC1

This patch enhances the talitos_desc struct with fields for SEC1.
SEC1 has only one header field, and has a 'next_desc' field in
addition.
This mixed descriptor will continue to fit SEC2, and for SEC1
we will recopy hdr value into hdr1 value in talitos_submit()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>