DRM/I915: Add enum hpd_pin to intel_encoder.

To clean up hotplug support we add a new enum to intel_encoder:
enum hpd_pin. It allows the encoder to request a hpd line but leave
the details which IRQ is responsible on which chipset generation
to i915_irq.c.
This way requesting hotplug support will become really simple on
the encoder/connector level.

Signed-off-by: Egbert Eich <eich@suse.de>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 276f665..54bc2ea 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -168,6 +168,7 @@
 	 * it is connected to in the pipe parameter. */
 	bool (*get_hw_state)(struct intel_encoder *, enum pipe *pipe);
 	int crtc_mask;
+	enum hpd_pin hpd_pin;
 };
 
 struct intel_panel {