ARM: dts: Revert enabling of twl configuration for n900

Commit 9188883f (ARM: dts: Enable twl4030 off-idle configuration
for selected omaps) allowed n900 to cut off core voltages during
off-idle. This however caused a regression where twl regulator
vaux1 was not getting enabled for the LCD panel as we are not
requesting it for the panel.

Turns out quite a few devices on n900 are using vaux1, and we need
to either stop idling it, or add proper regulator_get calls for all
users. But until we have a proper solution implemented and tested,
let's just disable the twl off-idle configuration for now for n900.

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Fixes: 9188883f (ARM: dts: Enable twl4030 off-idle configuration for selected omaps)
Signed-off-by: Tony Lindgren <tony@atomide.com>