drm/i915: Use intel_pipe_will_have_type() in ironlake_crtc_compute_clock()

ironlake_crtc_compute_clock() gets called during atomic compute phase,
so we must check the future pipe type instead of the current type.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448462131-13321-1-git-send-email-ville.syrjala@linux.intel.com


Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>