[VOL-1460]

- Imported protobuf definitions from pyvoltha at
  https://gerrit.opencord.org/gitweb?p=pyvoltha.git, commit hash:
  944aee71301b8ddb211b6e51d685f56d5c4a911b

- Imported upstream Google API protos from
  https://github.com/googleapis/googleapis, commit hash:
  5a90fbea68ce4a6e87c20d2df10df5ecd88299ff

- Fixed `import` paths and directory heirarchy in protobuf definitions
  to be compatible with both python 2 and 3.

- Created Makefile scaffold to generate language-specific bindings for
  python and go

Change-Id: Idd6b6b985a5eae4c38d40dd07ae78744c09e37f5
diff --git a/protos/voltha_protos/adapter.proto b/protos/voltha_protos/adapter.proto
new file mode 100644
index 0000000..9447510
--- /dev/null
+++ b/protos/voltha_protos/adapter.proto
@@ -0,0 +1,43 @@
+syntax = "proto3";
+
+option go_package = "github.com/opencord/voltha-go/protos/voltha";
+
+package voltha;
+
+import "google/protobuf/any.proto";
+import "voltha_protos/common.proto";
+import "voltha_protos/meta.proto";
+
+
+message AdapterConfig {
+
+    // Common adapter config attributes here
+    LogLevel.LogLevel log_level = 1;
+
+    // Custom (vendor-specific) configuration attributes
+    google.protobuf.Any additional_config = 64;
+
+}
+
+// Adapter (software plugin)
+message Adapter {
+
+    // Unique name of adapter, matching the python packate name under
+    // voltha/adapters.
+    string id = 1 [(access) = READ_ONLY];
+    string vendor = 2 [(access) = READ_ONLY];
+    string version = 3 [(access) = READ_ONLY];
+
+    // Adapter configuration
+    AdapterConfig config = 16;
+
+    // Custom descriptors and custom configuration
+    google.protobuf.Any additional_description = 64 [(access) = READ_ONLY];
+
+    repeated string logical_device_ids = 4;  // Logical devices "owned"
+
+}
+
+message Adapters {
+    repeated Adapter items = 1;
+}