crypto: api - Add crypto_requires_off helper

crypto: api - Add crypto_requires_off helper

BugLink: http://bugs.launchpad.net/bugs/1672544
commit 016df0abc56ec06d0c63c5318ef53e40738dea8b upstream.

This patch adds crypto_requires_off which is an extension of
crypto_requires_sync for similar bits such as NEED_FALLBACK.

Suggested-by: Marcelo Cerri <marcelo.cerri@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>