Make the fields of mbedtls_ecp_curve_info public

The whole point of this structure is to provide information, both for the
library's own sake and to applications.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 384d060..b2a2e32 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -147,13 +147,17 @@
 
 /**
  * Curve information, for use by other modules.
+ *
+ * The fields of this structure are part of the public API and can be
+ * accessed directly by applications. Future versions of the library may
+ * add extra fields or reorder existing fields.
  */
 typedef struct mbedtls_ecp_curve_info
 {
-    mbedtls_ecp_group_id MBEDTLS_PRIVATE(grp_id);    /*!< An internal identifier. */
-    uint16_t MBEDTLS_PRIVATE(tls_id);                /*!< The TLS NamedCurve identifier. */
-    uint16_t MBEDTLS_PRIVATE(bit_size);              /*!< The curve size in bits. */
-    const char *MBEDTLS_PRIVATE(name);               /*!< A human-friendly name. */
+    mbedtls_ecp_group_id grp_id;    /*!< An internal identifier. */
+    uint16_t tls_id;                /*!< The TLS NamedCurve identifier. */
+    uint16_t bit_size;              /*!< The curve size in bits. */
+    const char *name;               /*!< A human-friendly name. */
 } mbedtls_ecp_curve_info;
 
 /**