lib: crypto: allow to build crypyo in SPL

This commit adds the options:
- SPL_ASYMMETRIC_KEY_TYPE
- SPL_ASYMMETRIC_PUBLIC_KEY_SUBTYPE
- SPL_RSA_PUBLIC_KEY_PARSER

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index 6369baf..509bc28 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -8,6 +8,15 @@
 
 if ASYMMETRIC_KEY_TYPE
 
+config SPL_ASYMMETRIC_KEY_TYPE
+	bool "Asymmetric (public-key cryptographic) key Support within SPL"
+	depends on SPL
+	help
+	  This option provides support for a key type that holds the data for
+	  the asymmetric keys used for public key cryptographic operations such
+	  as encryption, decryption, signature generation and signature
+	  verification in the SPL.
+
 config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 	bool "Asymmetric public-key crypto algorithm subtype"
 	help
@@ -16,6 +25,15 @@
 	  appropriate hash algorithms (such as SHA-1) must be available.
 	  ENOPKG will be reported if the requisite algorithm is unavailable.
 
+config SPL_ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	bool "Asymmetric public-key crypto algorithm subtype within SPL"
+	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	help
+	  This option provides support for asymmetric public key type handling in the SPL.
+	  If signature generation and/or verification are to be used,
+	  appropriate hash algorithms (such as SHA-1) must be available.
+	  ENOPKG will be reported if the requisite algorithm is unavailable.
+
 config RSA_PUBLIC_KEY_PARSER
 	bool "RSA public key parser"
 	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
@@ -27,6 +45,17 @@
 	  public key data and provides the ability to instantiate a public
 	  key.
 
+config SPL_RSA_PUBLIC_KEY_PARSER
+	bool "RSA public key parser within SPL"
+	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	select SPL_ASN1_DECODER
+	select ASN1_COMPILER
+	select SPL_OID_REGISTRY
+	help
+	  This option provides support for parsing a blob containing RSA
+	  public key data and provides the ability to instantiate a public
+	  key in the SPL.
+
 config X509_CERTIFICATE_PARSER
 	bool "X.509 certificate parser"
 	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE