drm/i915/ns2501: Update from git working

[Thomas Richter <thor@math.tu-berlin.de>]

Hi Daniel, dear kernel developers,

just tried the 3.12.rc3+ from the intel-drm git. This version *worked* 
again, pretty much the same way the 3.10.10 "worked".

Side effects are, however, quite the same when you connect an external 
monitor:

If connected while the gdm login screen is on, the external monitor 
works fine with the internal TFT (mirroring is turned on). Resolutions
1024x768 and 800x600 are fine, switching to 640x480 locks up the 
internal DVO, the external monitor keeps working. Note that the DVO
does *not* lock up if the external monitor is not connect (probably a 
frequency issue, need to check).

Booting with the external monitor connected creates a "locked up" 
display on the internal TFT, and a flickering display on the external
screen as if the watermark levels are not set correctly. The external 
screen shows a horizontal offset of approximately half the screen
width (scrolled to the right), but jumps back to its correct position 
irregularly. Note that this type of flickering is different from the flicker
created by panning on the 835GM (already reported this problem), which 
shows a regular 30Hz flicker.

Once the gdm comes up, the internal TFT keeps dead, and the external 
shows only a black screen but with a working mouse pointer.
Logging in blindly restores a working screen on both monitors.

So thanks for the update, seems to have worked, but is still not working 
perfectly. External monitors are not supported correctly,
and panning is still a problem, even with a "linear" framebuffer.

Greetings,
     Thomas