crypto: chelsio - Remove declaration of static function from header

It fixes compilation warning introduced in commit

Fixes: 5110e655

 ("crypto: chelsio - Split Hash requests for...")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Harsh Jain <harsh@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>