drm/i915: Fix i915_ggtt_view_equal to handle rotation correctly

drm/i915: Fix i915_ggtt_view_equal to handle rotation correctly

The rotated view depends upon the rotation paramters, but thus far we
didn't bother checking for those. This seems to have been an issue
ever since this was introduce in

commit ad2d81acffdce06d89b7e2dc363fc7a53ac3ca61
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Wed Dec 10 17:27:58 2014 +0000

    drm/i915: Infrastructure for supporting different GGTT views per object

But userspace is allowed to reuse framebuffer backing storage with
different framebuffers with different pixel formats/stride/whatever.
And e.g. SNA indeed does this. Hence we must check for all the
paramters to match, not just that it's rotated.

v2: intel_plane_obj_offset also needs to construct the full view, to
avoid fallout since they don't fully match.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1444834266-12689-3-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>