Add suspend/resume to the core class and remove all the now unneeded
code from various drivers. Originally the class code couldn't support
suspend/resume but since class_device can there is no reason for
each driver doing its own suspend/resume anymore.

Driver for PC Engines ALIX.2 and ALIX.3 LEDs.

Signed-off-by: Constantin Baranov <const@mimas.ru>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>