lib/crc: remove unnecessary prompt for CONFIG_CRC32 and drop 'default y'

All modules that need CONFIG_CRC32 already select it, so there is no
need to bother users about the option, nor to default it to y.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250401221600.24878-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

arch/sh/configs/edosk7705_defconfig

@@ -33,4 +33,3 @@ CONFIG_CMDLINE_FROM_BOOTLOADER=y
 # CONFIG_PROC_FS is not set
 # CONFIG_SYSFS is not set
 # CONFIG_ENABLE_MUST_CHECK is not set
-# CONFIG_CRC32 is not set

arch/sh/configs/kfr2r09-romimage_defconfig

@@ -49,4 +49,3 @@ CONFIG_TMPFS=y
 # CONFIG_NETWORK_FILESYSTEMS is not set
 # CONFIG_ENABLE_MUST_CHECK is not set
 CONFIG_DEBUG_FS=y
-# CONFIG_CRC32 is not set

arch/sh/configs/sh7724_generic_defconfig

@@ -39,4 +39,3 @@ CONFIG_UIO_PDRV_GENIRQ=y
 # CONFIG_SYSFS is not set
 # CONFIG_MISC_FILESYSTEMS is not set
 # CONFIG_ENABLE_MUST_CHECK is not set
-# CONFIG_CRC32 is not set

arch/sh/configs/sh7770_generic_defconfig

@@ -41,4 +41,3 @@ CONFIG_UIO_PDRV_GENIRQ=y
 # CONFIG_SYSFS is not set
 # CONFIG_MISC_FILESYSTEMS is not set
 # CONFIG_ENABLE_MUST_CHECK is not set
-# CONFIG_CRC32 is not set

lib/Kconfig

@@ -177,14 +177,8 @@ config CRC_ITU_T
 	  functions require M here.
 
 config CRC32
-	tristate "CRC32/CRC32c functions"
-	default y
+	tristate
 	select BITREVERSE
-	help
-	  This option is provided for the case where no in-kernel-tree
-	  modules require CRC32/CRC32c functions, but a module built outside
-	  the kernel tree does. Such modules that use library CRC32/CRC32c
-	  functions require M here.
 
 config ARCH_HAS_CRC32
 	bool