Support tofino build for P4_14 test programs

Also, modified programs such that both the P4_14 and P4_16 versions
produce the same forwarding behaviour and control API (i.e. P4Info)

Change-Id: I90b7fdfedff5f2a89e0f2295d32e2bb61cd0e0eb
diff --git a/tools/test/p4src/p4-16/default.p4 b/tools/test/p4src/p4-16/default.p4
index b977d91..c76cbf7 100644
--- a/tools/test/p4src/p4-16/default.p4
+++ b/tools/test/p4src/p4-16/default.p4
@@ -54,10 +54,10 @@
             set_egress_port(standard_metadata);
             send_to_cpu(standard_metadata);
             do_ecmp();
-            drop(standard_metadata);
+            _drop(standard_metadata);
         }
         counters = table0_counter;
-        default_action = drop(standard_metadata);
+        default_action = _drop(standard_metadata);
     }
 
     action_selector(HashAlgorithm.crc16, 32w64, 32w16) ecmp_selector;