[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/golang.org/x/sys/unix/asm_solaris_amd64.s b/vendor/golang.org/x/sys/unix/asm_solaris_amd64.s
index ded8260..f8c5394 100644
--- a/vendor/golang.org/x/sys/unix/asm_solaris_amd64.s
+++ b/vendor/golang.org/x/sys/unix/asm_solaris_amd64.s
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !gccgo
+//go:build gc
+// +build gc
 
 #include "textflag.h"