Make test function name more accurate

Signed-off-by: Paul Elliott <paul.elliott@arm.com>

tests/suites/test_suite_ssl.data

@@ -4781,4 +4781,4 @@ Test configuration of groups for DHE through mbedtls_ssl_conf_groups()
 conf_group:
 
 Test accessor into timing_delay_context
-timing_accessor
+timing_final_delay_accessor

tests/suites/test_suite_ssl.function

@@ -5279,7 +5279,7 @@ void conf_group()
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_TIMING_C:MBEDTLS_HAVE_TIME */
-void timing_accessor( )
+void timing_final_delay_accessor( )
 {
     mbedtls_timing_delay_context    delay_context;