lib/crc: remove unnecessary prompt for CONFIG_CRC4

All modules that need CONFIG_CRC4 already select it, so there is no need
to bother users about the option.

Acked-by: Ard Biesheuvel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Eric Biggers <[email protected]>

Author: ebiggers

arch/s390/configs/debug_defconfig

@@ -815,7 +815,6 @@ CONFIG_SYSTEM_BLACKLIST_KEYRING=y
 CONFIG_CORDIC=m
 CONFIG_CRYPTO_LIB_CURVE25519=m
 CONFIG_CRYPTO_LIB_CHACHA20POLY1305=m
-CONFIG_CRC4=m
 CONFIG_CRC7=m
 CONFIG_CRC8=m
 CONFIG_RANDOM32_SELFTEST=y

arch/s390/configs/defconfig

@@ -803,7 +803,6 @@ CONFIG_CORDIC=m
 CONFIG_PRIME_NUMBERS=m
 CONFIG_CRYPTO_LIB_CURVE25519=m
 CONFIG_CRYPTO_LIB_CHACHA20POLY1305=m
-CONFIG_CRC4=m
 CONFIG_CRC7=m
 CONFIG_CRC8=m
 CONFIG_XZ_DEC_MICROLZMA=y

lib/Kconfig

@@ -209,12 +209,7 @@ config CRC64_ARCH
 	default CRC64 if ARCH_HAS_CRC64 && CRC_OPTIMIZATIONS
 
 config CRC4
-	tristate "CRC4 functions"
-	help
-	  This option is provided for the case where no in-kernel-tree
-	  modules require CRC4 functions, but a module built outside
-	  the kernel tree does. Such modules that use library CRC4
-	  functions require M here.
+	tristate
 
 config CRC7
 	tristate "CRC7 functions"