drm/i915: Apply i830 errata for cursor alignment

i830 requires 32bpp cursors to be aligned to 16KB, so we have to expose
the alignment parameter to i915_gem_attach_phys_object().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --cc drivers/gpu/drm/i915/i915_drv.h
Simple merge

diff --cc drivers/gpu/drm/i915/i915_gem.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_display.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_overlay.c
Simple merge