samples: counter: add esp32c2 soc overlay

esp8684_devkitm board build is failing due to
missing overlay file, which enables timer/counter.

Signed-off-by: Sylvio Alves <[email protected]>

Author: sylvioalves

samples/drivers/counter/alarm/socs/esp32c2.overlay

@@ -0,0 +1,6 @@
+&timer0 {
+	status = "okay";
+	counter {
+		status = "okay";
+	};
+};