Rename MBEDTLS_X509_INFO to !MBEDTLS_X509_REMOVE_INFO

The introduction of positive options to control the presence
of pre-existing functionality breaks the build for users of
handwritten configurations.

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/library/x509_csr.c b/library/x509_csr.c
index 0a5d2cb..b78c042 100644
--- a/library/x509_csr.c
+++ b/library/x509_csr.c
@@ -323,7 +323,7 @@
 }
 #endif /* MBEDTLS_FS_IO */
 
-#if defined(MBEDTLS_X509_INFO)
+#if !defined(MBEDTLS_X509_REMOVE_INFO)
 #define BEFORE_COLON    14
 #define BC              "14"
 /*
@@ -368,7 +368,7 @@
 
     return( (int) ( size - n ) );
 }
-#endif /* MBEDTLS_X509_INFO */
+#endif /* MBEDTLS_X509_REMOVE_INFO */
 
 /*
  * Initialize a CSR