[UPSTREAM] Move backlight handling out of pcf50633 driver

[Michael 'Mickey' Lauer]

I don't want to comment on the political issues here, but having worked or at 
least read a number of software stacks on top of kernel 2.6, I can say that 
all users of the brightness class interface _I_ have seen are using the 
max_brightness attribute.

I therefore see no reason to worry about changes, although I clearly want to 
state that I don't see a reason to change it in the first place. The 
brightness class interface exposes the hardware capability of a device, which 
is inherently device specific, that's why max_brightness has been an 
attribute since this class first hit mainline.

Bottom line: Don't change it in kernel. If you decide against my 
recommendation, don't worry either, userland will not break.

Cheers,
-- 
:M: