drm/i914: Refactor vlv_display_irq_postinstall()

Split the vlv display irq postinstall code to a separate function so
that we can share it with chv.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
1 file changed