leds: LED driver for Intel NAS SS4200 series (v5)

leds: LED driver for Intel NAS SS4200 series (v5)

This code is based on a driver that came in the "Open-source
and GPL components" download here:

http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Server+Products&ProductLine=Intel%C2%AE+Storage+Systems&ProductProduct=Intel%C2%AE+Entry+Storage+System+SS4200-E&OSVersion=OS+Independent

It was in a file called nasgpio.c inside of a second zip file
called SS4200-E_Linux_SIO_Driver-v1.4.zip and is based on this
updated to use the LED subsystem with the ioctl and hardware
monitor support removed.

I don't have any need for brightness
control, and its code is *completely* separate from the on/off
controls implemented here.  If anyone else wants it, I'd be
happy to look into adding it, but I don't care enough for now.

Except for the probe routines, I rewrote most of it.  I also
Note that I don't have any hardware documentation except for
the original driver.

Thanks go to Arjan for his help in getting the original source
for this released and for chasing down some licensing issues.

Signed-off-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>