Update event message

Updated the event message to match what `:circuits_gpio` does to have
consistency across libraries.

Author: mattludwigs

README.md

@@ -90,7 +90,7 @@ Circuits.GPIO.Chip.listen_event("gpiochip0", 27)
 When an event is received from the line it will be in the form of:
 
 ```
-{:circuits_cdev, pin_number, new_value, timestamp}
+{:circuits_cdev, pin_number, timestamp, new_value}
 ```
 
 

lib/chip/events.ex

@@ -50,15 +50,16 @@ defmodule Circuits.GPIO.Chip.Events do
     %Event{
       handle: event_handle,
       listener: listener,
-      last_event: last_event
+      last_event: last_event,
+      offset: offset
     } = event = Map.fetch!(state, event_ref)
 
     {:ok, event_value, timestamp} = Nif.read_event_data_nif(event_handle, event_data_ref)
 
     if event_value != last_event do
       send(
         listener,
-        {:circuits_gpio_chip, :event, event_value_to_offset_value(event_value), timestamp}
+        {:circuits_cdev, offset, timestamp, event_value_to_offset_value(event_value)}
       )
     end