Move accessor definition

Move the definition of the accessor so that it is not defined
within the MBEDTLS_X509_CRT_WRITE_C guards. Thus remove the
dependency from the test and test cases.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index 6ed5ea1..29057b7 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -400,7 +400,7 @@
  * END_DEPENDENCIES
  */
 
-/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_WRITE_C */
+/* BEGIN_CASE */
 void x509_accessor_ext_types( int ext_type, int has_ext_type )
 {
     mbedtls_x509_crt crt;