gma500: display displaced vertically by a few lines

[Holger Schurig]

Okay, I found the patch that produces my regression:

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>From bc794829141f28e14fe7d0e07e35870bd9aee78c Mon Sep 17 00:00:00 2001
From: Patrik Jakobsson <patrik.r.jakobsson at gmail.com>
Date: Mon, 21 May 2012 15:27:30 +0100
Subject: [PATCH 143/209] gma500: handle poulsbo cursor restriction

Poulsbo needs a physical address in the cursor base register. We allocate a
stolen memory buffer and copy the cursor image provided by userspace into it.
When/If we get our own userspace driver we can map this stolen memory directly.
The patch also adds a mark in chip ops so we can identify devices that has this
requirement.
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When I modify the patch that psb_chip_ops.cursor_needs_phys doesn't
get initialized to 1, then the display doesn't get displaced.