crypto: testmgr - Do not test internal algorithms

Currently we manually filter out internal algorithms using a list
in testmgr.  This is dangerous as internal algorithms cannot be
safely used even by testmgr.  This patch ensures that they're never
processed by testmgr at all.

This patch also removes an obsolete bypass for nivciphers which
no longer exist.

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