Initial: shell out RPC library

Author: facchinm

variants/ENVIE_M4/RPC.cpp renamed to libraries/RPC/RPC.cpp

@@ -26,6 +26,7 @@ extern "C" {
 #endif
 #define boolean   boolean_t
 #include "openamp.h"
+#include "arduino_openamp.h"
 #undef boolean
 #ifdef bool
 #define boolean   bool

variants/ENVIE_M4/RPC_client.h renamed to libraries/RPC/RPC_client.h

@@ -0,0 +1,22 @@
+#include "Arduino.h"
+#include "RPC_internal.h"
+
+#define LED_BUILTIN PK_5
+
+void setup() {
+  // put your setup code here, to run once:
+  RPC1.begin();
+  //Serial.begin(115200);
+  pinMode(LED_BUILTIN, OUTPUT);
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  digitalWrite(LED_BUILTIN, HIGH);
+  delay(1000);
+  digitalWrite(LED_BUILTIN, LOW);
+  delay(1000);
+  RPC1.println("test");
+  auto res = RPC1.client.call("add", 12, 45).as<int>();;
+  RPC1.println(res);
+}