README: Add AS6706T to compatible devices, mark AS5404T as untested

AS6706T has been confirmed as working by several users so it should be
listed.
AS5404T most probably is very similar to the (tested) AS6704T, like
AS5402T is very similar to AS6702T, but so far hasn't been confirmed
to work so I added `(NOT TESTED!)` to that entry

Author: DanielGibson

README.md

@@ -34,8 +34,8 @@ On many systems, ASUSTOR uses a mix of IT87 and CPU GPIOs to control leds and bu
 - AS6104T (NOT TESTED!)
 - AS6204T
 - AS6602T, AS6604T (NOT TESTED!)
-- AS6702T, AS6704T
-- AS5402T, AS5404T
+- AS6702T, AS6704T, AS6706T
+- AS5402T, AS5404T (NOT TESTED!)
 - FS6706T (NOT TESTED!), FS6712X
 - .. possibly more, if they're similar enough.