crypto: algif_rng - enable RNG interface compilation

Enable compilation of the RNG AF_ALG support and provide a Kconfig
option to compile the RNG AF_ALG support.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 1618468..50f4da4 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1514,6 +1514,15 @@
 	  This option enables the user-spaces interface for symmetric
 	  key cipher algorithms.
 
+config CRYPTO_USER_API_RNG
+	tristate "User-space interface for random number generator algorithms"
+	depends on NET
+	select CRYPTO_RNG
+	select CRYPTO_USER_API
+	help
+	  This option enables the user-spaces interface for random
+	  number generator algorithms.
+
 config CRYPTO_HASH_INFO
 	bool