crypto: caam - only export the state we really need to export

Avoid exporting lots of state by only exporting what we really require,
which is the buffer containing the set of pending bytes to be hashed,
number of pending bytes, the context buffer, and the function pointer
state.  This reduces down the exported state size to 216 bytes from
576 bytes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>