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 <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250304230712.167600-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

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"