crypto: tcrypt - Allow speed testing of arbitrary hash functions

This patch allows the testing of arbitrary hash functions specified
by the alg module parameter by using them in mode 300 (for sync hash)
and mode 400 (for async hash).

For example, you could do
	modprobe tcrypt mode=300 alg='vmac(aes)'

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