kmemleak: fix kconfig for crc32 build error

kmemleak uses crc32 functions so it needs to select CRC32.
Fixes build error:

kmemleak.c:(.text+0x7ce62): undefined reference to `crc32_le'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

lib/Kconfig.debug

@@ -352,6 +352,7 @@ config DEBUG_KMEMLEAK
 	select DEBUG_FS if SYSFS
 	select STACKTRACE if STACKTRACE_SUPPORT
 	select KALLSYMS
+	select CRC32
 	help
 	  Say Y here if you want to enable the memory leak
 	  detector. The memory allocation/freeing is traced in a way