drm/i915/skl: Teach pin_and_fence_fb_obj() about Y tiling constraints

1Mb!

v2: Rebased for addfb2 interface. (Tvrtko Ursulin)
v3: Rebased for fb modifier changes. (Tvrtko Ursulin)

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>