Add the ability to turn FIPS-compliant mode on or off at boot

In order to be FIPS compliant, several check may need to be preformed that may
be construed as unusefull in a non-compliant mode.  This patch allows us to set
a kernel flag incating that we are running in a fips-compliant mode from boot
up.  It also exports that mode information to user space via a sysctl
(/proc/sys/crypto/fips_enabled).

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