crypto: sun4i-ss - support the Security System PRNG

The Security System has a PRNG, this patch adds support for it via
crypto_rng.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 4b75084..5db825a 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -616,6 +616,14 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called sun4i-ss.
 
+config CRYPTO_DEV_SUN4I_SS_PRNG
+	bool "Support for Allwinner Security System PRNG"
+	depends on CRYPTO_DEV_SUN4I_SS
+	select CRYPTO_RNG
+	help
+	  Select this option if you want to provide kernel-side support for
+	  the Pseudo-Random Number Generator found in the Security System.
+
 config CRYPTO_DEV_ROCKCHIP
 	tristate "Rockchip's Cryptographic Engine driver"
 	depends on OF && ARCH_ROCKCHIP