Increase test suite timeout

Increase the test suite timeouit from 180 seconds, to 800 seconds,
since some tests consume more time, even if all tests are skipped.
diff --git a/tests/suites/target_test.function b/tests/suites/target_test.function
index d430d9d..a0d6653 100644
--- a/tests/suites/target_test.function
+++ b/tests/suites/target_test.function
@@ -368,7 +368,7 @@
     void ** params = NULL;
     uint8_t * data = NULL, * p = NULL;
 
-    GREENTEA_SETUP( 180, "mbedtls_test" );
+    GREENTEA_SETUP( 800, "mbedtls_test" );
     greentea_send_kv( "GO", " " );
 
     while ( 1 )