drm/gma500/cdv: Unpin framebuffer on crtc disable

drm/gma500/cdv: Unpin framebuffer on crtc disable

commit 22e7c385a80d771aaf3a15ae7ccea3b0686bbe10 upstream.

The framebuffer needs to be unpinned in the crtc->disable callback
because of previous pinning in psb_intel_pipe_set_base(). This will fix
a memory leak where the framebuffer was released but not unpinned
properly. This patch only affects Cedarview.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=889511
Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=812113
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>