Fixing packet_io and regenerating default.p4 for tofino

Change-Id: I5c2c6565f71a13b375a8ec8da864e9157b8e56ed
diff --git a/tools/test/p4src/p4-14/p4c-out/default.p4info b/tools/test/p4src/p4-14/p4c-out/default.p4info
index 89acacf..35d6c00 100644
--- a/tools/test/p4src/p4-14/p4c-out/default.p4info
+++ b/tools/test/p4src/p4-14/p4c-out/default.p4info
@@ -142,7 +142,7 @@
   spec {
     unit: PACKETS
   }
-  size: 511
+  size: 254
 }
 counters {
   preamble {
@@ -154,7 +154,7 @@
   spec {
     unit: PACKETS
   }
-  size: 511
+  size: 254
 }
 direct_counters {
   preamble {