crypto: fips - Depend on ansi_cprng

What about something like this?  It defaults the CPRNG to m and makes FIPS
dependent on the CPRNG.  That way you get a module build by default, but you can
change it to y manually during config and still satisfy the dependency, and if
you select N it disables FIPS as well.  I rather like that better than making
FIPS a tristate.  I just tested it out here and it seems to work well.  Let me
know what you think

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>