crypto: rng - Remove old low-level rng interface

Now that all rng implementations have switched over to the new
interface, we can remove the old low-level interface.

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

diff --cc crypto/rng.c
Simple merge

diff --cc include/crypto/internal/rng.h
Simple merge

diff --cc include/crypto/rng.h
Simple merge

diff --cc include/linux/crypto.h
Simple merge