crypto: talitos - using helpers for all talitos_ptr operations

Use helper for all modifications to talitos_ptr in preparation to
the implementation of AEAD for SEC1

to_talitos_ptr_extent_clear() has been removed in favor of
to_talitos_ptr_ext_set() to set any value and
to_talitos_ptr_ext_or() to or the extent field with a value
name has been shorten to help keeping single lines of 80 chars

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