drm/i915: call intel_tile_height with correct parameter

In skylake update plane functions, intel_tile_height() is called with
bits_per_pixel instead of pixel_format. Correcting it.

Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
[danvet: Fixup alignment.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>