crypto: ansi_cprng - Remove unused ansi_cprng algorithm

Remove ansi_cprng, since it's obsolete and unused, as confirmed at
https://lore.kernel.org/r/aQxpnckYMgAAOLpZ@gondor.apana.org.au/

This was originally added in 2008, apparently as a FIPS approved random
number generator.  Whether this has ever belonged upstream is
questionable.  Either way, ansi_cprng is no longer usable for this
purpose, since it's been superseded by the more modern algorithms in
crypto/drbg.c, and FIPS itself no longer allows it.  (NIST SP 800-131A
Rev 1 (2015) says that RNGs based on ANSI X9.31 will be disallowed after
2015.  NIST SP 800-131A Rev 2 (2019) confirms they are now disallowed.)

Therefore, there is no reason to keep it around.

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Haotian Zhang <vulab@iscas.ac.cn>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: Eric Biggers

Documentation/crypto/userspace-if.rst

@@ -6605,7 +6605,6 @@ CRYPTOGRAPHIC RANDOM NUMBER GENERATOR
 M:	Neil Horman <nhorman@tuxdriver.com>
 L:	linux-crypto@vger.kernel.org
 S:	Maintained
-F:	crypto/ansi_cprng.c
 F:	crypto/rng.c
 
 CS3308 MEDIA DRIVER

MAINTAINERS

@@ -233,4 +233,3 @@ CONFIG_RCU_CPU_STALL_TIMEOUT=60
 CONFIG_DEBUG_USER=y
 CONFIG_CRYPTO_GCM=y
 CONFIG_CRYPTO_SHA256=y
-# CONFIG_CRYPTO_ANSI_CPRNG is not set

arch/arm/configs/axm55xx_defconfig

@@ -75,5 +75,4 @@ CONFIG_MINIX_FS=y
 CONFIG_DEBUG_USER=y
 CONFIG_DEBUG_LL=y
 CONFIG_EARLY_PRINTK=y
-# CONFIG_CRYPTO_ANSI_CPRNG is not set
 # CONFIG_CRYPTO_HW is not set

arch/arm/configs/clps711x_defconfig

@@ -126,7 +126,6 @@ CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_SHA512=y
 CONFIG_CRYPTO_DEFLATE=y
 CONFIG_CRYPTO_LZO=y
-# CONFIG_CRYPTO_ANSI_CPRNG is not set
 CONFIG_CRYPTO_DEV_MARVELL_CESA=y
 CONFIG_PRINTK_TIME=y
 # CONFIG_DEBUG_BUGVERBOSE is not set

arch/arm/configs/dove_defconfig

@@ -119,4 +119,3 @@ CONFIG_DEBUG_SPINLOCK=y
 CONFIG_DEBUG_MUTEXES=y
 CONFIG_DEBUG_USER=y
 CONFIG_DEBUG_LL=y
-# CONFIG_CRYPTO_ANSI_CPRNG is not set

arch/arm/configs/ep93xx_defconfig

@@ -92,4 +92,3 @@ CONFIG_NLS_UTF8=m
 CONFIG_DEBUG_KERNEL=y
 # CONFIG_FTRACE is not set
 CONFIG_DEBUG_LL=y
-# CONFIG_CRYPTO_ANSI_CPRNG is not set

arch/arm/configs/jornada720_defconfig

@@ -228,7 +228,6 @@ CONFIG_CRYPTO_DES=y
 CONFIG_CRYPTO_CBC=y
 CONFIG_CRYPTO_CTR=y
 CONFIG_CRYPTO_XCBC=y
-CONFIG_CRYPTO_ANSI_CPRNG=y
 CONFIG_CRYPTO_USER_API_HASH=y
 CONFIG_CRYPTO_USER_API_SKCIPHER=y
 CONFIG_DMA_CMA=y

arch/arm/configs/keystone_defconfig

@@ -177,7 +177,6 @@ CONFIG_NLS_CODEPAGE_437=y
 CONFIG_NLS_ASCII=y
 CONFIG_NLS_ISO8859_1=y
 CONFIG_NLS_UTF8=y
-CONFIG_CRYPTO_ANSI_CPRNG=y
 # CONFIG_CRYPTO_HW is not set
 CONFIG_PRINTK_TIME=y
 CONFIG_DYNAMIC_DEBUG=y

arch/arm/configs/lpc32xx_defconfig

@@ -78,4 +78,3 @@ CONFIG_DEBUG_USER=y
 CONFIG_DEBUG_LL=y
 CONFIG_DEBUG_MMP_UART3=y
 CONFIG_EARLY_PRINTK=y
-# CONFIG_CRYPTO_ANSI_CPRNG is not set