crypto: cryptomgr - Test ciphers using ECB

As it is we only test ciphers when combined with a mode.  That means
users that do not invoke a mode of operations may get an untested
cipher.

This patch tests all ciphers using the ECB mode so that simple cipher
users such as ansi-cprng are also protected.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>