pkcs7: Add dependecy on MBEDTLS_MD_C

Signed-off-by: Nick Child <nick.child@ibm.com>
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index dcb6392..e5f8b89 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -992,7 +992,8 @@
 #if defined(MBEDTLS_PKCS7_C) && ( ( !defined(MBEDTLS_ASN1_PARSE_C) ) || \
     ( !defined(MBEDTLS_OID_C) ) || ( !defined(MBEDTLS_PK_PARSE_C) ) || \
     ( !defined(MBEDTLS_X509_CRT_PARSE_C) ) ||\
-    ( !defined(MBEDTLS_X509_CRL_PARSE_C) ) || ( !defined(MBEDTLS_BIGNUM_C) ) )
+    ( !defined(MBEDTLS_X509_CRL_PARSE_C) ) || ( !defined(MBEDTLS_BIGNUM_C) ) \
+    ( !defined(MBEDTLS_MD_C) ) )
 #error  "MBEDTLS_PKCS7_C is defined, but not all prerequisites"
 #endif
 
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 45dd274..84dcf47 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -2669,7 +2669,8 @@
  * Module:  library/pkcs7.c
  *
  * Requires: MBEDTLS_ASN1_PARSE_C, MBEDTLS_OID_C, MBEDTLS_PK_PARSE_C,
- *           MBEDTLS_X509_CRT_PARSE_C MBEDTLS_X509_CRL_PARSE_C, MBEDTLS_BIGNUM_C
+ *           MBEDTLS_X509_CRT_PARSE_C MBEDTLS_X509_CRL_PARSE_C,
+ *           MBEDTLS_BIGNUM_C, MBEDTLS_MD_C
  *
  * This module is required for the PKCS7 parsing modules.
  */