Reduce code size when mbedtls_x509_*_info() unused

Introduce MBEDTLS_X509_INFO to indicate the availability of the
mbedtls_x509_*_info() function and closely related APIs. When this is
not defined, also omit name and description from
mbedtls_oid_descriptor_t, and omit OID arrays, macros, and types that
are entirely unused. This saves several KB of code space.

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
Signed-off-by: Chris Jones <christopher.jones@arm.com>
diff --git a/tests/suites/test_suite_oid.function b/tests/suites/test_suite_oid.function
index 9e8d437..8c42d70 100644
--- a/tests/suites/test_suite_oid.function
+++ b/tests/suites/test_suite_oid.function
@@ -6,7 +6,7 @@
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
- * depends_on:MBEDTLS_OID_C
+ * depends_on:MBEDTLS_OID_C:MBEDTLS_X509_INFO
  * END_DEPENDENCIES
  */