nb/intel/sandybridge: Use understandable values for PWM backlight

This gets rid of setting the register values from the devicetree and
makes it possible to use sensible values in the devicetree.

TODO update autoport.

Untested

Change-Id: I7eb69d9efdccede02fdd3771b3deab536050bfa4
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
---
M src/mainboard/apple/macbookair4_2/devicetree.cb
M src/mainboard/asrock/b75pro3-m/devicetree.cb
M src/mainboard/compulab/intense_pc/devicetree.cb
M src/mainboard/google/butterfly/devicetree.cb
M src/mainboard/google/link/devicetree.cb
M src/mainboard/google/parrot/devicetree.cb
M src/mainboard/google/stout/devicetree.cb
M src/mainboard/hp/2570p/devicetree.cb
M src/mainboard/hp/2760p/devicetree.cb
M src/mainboard/hp/8460p/devicetree.cb
M src/mainboard/hp/8470p/devicetree.cb
M src/mainboard/hp/folio_9470m/devicetree.cb
M src/mainboard/hp/revolve_810_g1/devicetree.cb
M src/mainboard/lenovo/l520/devicetree.cb
M src/mainboard/lenovo/s230u/devicetree.cb
M src/mainboard/lenovo/t420/devicetree.cb
M src/mainboard/lenovo/t420s/devicetree.cb
M src/mainboard/lenovo/t430/devicetree.cb
M src/mainboard/lenovo/t430s/devicetree.cb
M src/mainboard/lenovo/t430s/variants/t431s/overridetree.cb
M src/mainboard/lenovo/t520/variants/t520/devicetree.cb
M src/mainboard/lenovo/t520/variants/w520/devicetree.cb
M src/mainboard/lenovo/t530/variants/t530/devicetree.cb
M src/mainboard/lenovo/t530/variants/w530/devicetree.cb
M src/mainboard/lenovo/x131e/devicetree.cb
M src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
M src/mainboard/lenovo/x220/devicetree.cb
M src/mainboard/lenovo/x230/devicetree.cb
M src/mainboard/roda/rv11/variants/rv11/devicetree.cb
M src/mainboard/roda/rv11/variants/rw11/devicetree.cb
M src/mainboard/samsung/lumpy/devicetree.cb
M src/mainboard/sapphire/pureplatinumh61/devicetree.cb
M src/northbridge/intel/sandybridge/chip.h
M src/northbridge/intel/sandybridge/gma.c
34 files changed, 92 insertions(+), 72 deletions(-)