lib: crypto: add pkcs7 message parser

Imported from linux kernel v5.3:
 pkcs7.asn1 without changes
 pkcs7.h with changes marked as __UBOOT__
 pkcs7_parser.h without changes
 pkcs7_parser.c with changes marked as __UBOOT__

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index aeb599c..2b221b9 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -39,4 +39,14 @@
 	  data and provides the ability to instantiate a crypto key from a
 	  public key packet found inside the certificate.
 
+config PKCS7_MESSAGE_PARSER
+	bool "PKCS#7 message parser"
+	depends on X509_CERTIFICATE_PARSER
+	select ASN1_DECODER
+	select ASN1_COMPILER
+	select OID_REGISTRY
+	help
+	  This option provides support for parsing PKCS#7 format messages for
+	  signature data and provides the ability to verify the signature.
+
 endif # ASYMMETRIC_KEY_TYPE