crypto: ansi_cprng - ANSI X9.31 DRNG is not allowed in FIPS 140-2

As per update of the FIPS 140-2 Annex C supported by SP800-131A, the
ANSI X9.31 DRNG is not an allowed cipher in FIPS mode any more.

CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>