crypto: rsa - add a new rsa generic implementation

Add a new rsa generic SW implementation.
This implements only cryptographic primitives.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>

Added select on ASN1.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index eb0aca4..d6b2a8b 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -100,6 +100,14 @@
 	select CRYPTO_AKCIPHER2
 	select CRYPTO_ALGAPI
 
+config CRYPTO_RSA
+	tristate "RSA algorithm"
+	select AKCIPHER
+	select MPILIB
+	select ASN1
+	help
+	  Generic implementation of the RSA public key algorithm.
+
 config CRYPTO_MANAGER
 	tristate "Cryptographic algorithm manager"
 	select CRYPTO_MANAGER2