initial support for elecrow thinknode m7

variants/thinknode_m7/ThinkNodeM7Board.cpp

@@ -0,0 +1,17 @@
+#include "ThinkNodeM7Board.h"
+
+void ThinkNodeM7Board::begin() {
+  ESP32Board::begin();
+}
+
+void ThinkNodeM7Board::enterDeepSleep(uint32_t secs, int pin_wake_btn) {
+  esp_deep_sleep_start();
+}
+
+void ThinkNodeM7Board::powerOff()  {
+  enterDeepSleep(0);
+}
+
+const char* ThinkNodeM7Board::getManufacturerName() const {
+  return "Elecrow ThinkNode M7";
+}