[CRYPTO] ctr: Remove default M

NO other block mode is M by default.
Signed-off-by: NSebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

crypto/Kconfig

@@ -199,7 +199,6 @@ config CRYPTO_CTR
 	tristate "CTR support"
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_MANAGER
-	default m
 	help
 	  CTR: Counter mode
 	  This block cipher algorithm is required for IPSec.