reinstate M1 Backlight (#6484)

src/graphics/EInkDisplay2.cpp

@@ -128,8 +128,13 @@ bool EInkDisplay::connect()
 #ifdef PIN_EINK_EN
     // backlight power, HIGH is backlight on, LOW is off
     pinMode(PIN_EINK_EN, OUTPUT);
+#ifdef ELECROW_ThinkNode_M1
+    // ThinkNode M1 has a hardware dimmable backlight. Start enabled
+    digitalWrite(PIN_EINK_EN, HIGH);
+#else
     digitalWrite(PIN_EINK_EN, LOW);
 #endif
+#endif
 
 #if defined(TTGO_T_ECHO) || defined(ELECROW_ThinkNode_M1)
     {