modules: mbedtls: Provide CONFIG_MBEDTLS_ASN1_PARSE_C

The commit exports control of MBEDTLS_ASN1_PARSE_C, in mbedTLS
module, via Kconfig.
This allows applications to use ASN1 parser independently from
other functions.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

modules/mbedtls/Kconfig.tls-generic

@@ -138,6 +138,7 @@ config MBEDTLS_ECDH_C
 config MBEDTLS_ECDSA_C
 	bool "Elliptic curve DSA library"
 	depends on MBEDTLS_ECP_C
+	select MBEDTLS_ASN1_PARSE_C
 
 config MBEDTLS_ECJPAKE_C
 	bool "Elliptic curve J-PAKE library"
@@ -373,6 +374,11 @@ config MBEDTLS_MD
 config MBEDTLS_GENPRIME_ENABLED
 	bool "prime-number generation code."
 
+config MBEDTLS_ASN1_PARSE_C
+	bool "Support for ASN1 parser functions"
+	help
+	  Enable ASN1 parser functions.
+
 config MBEDTLS_PEM_CERTIFICATE_FORMAT
 	bool "Support for PEM certificate format"
 	help

modules/mbedtls/configs/config-tls-generic.h

@@ -431,7 +431,7 @@
 #define MBEDTLS_PK_C
 #endif
 
-#if defined(MBEDTLS_ECDSA_C) || defined(MBEDTLS_X509_USE_C)
+#if defined(CONFIG_MBEDTLS_ASN1_PARSE_C) || defined(MBEDTLS_X509_USE_C)
 #define MBEDTLS_ASN1_PARSE_C
 #endif