drm/nv50: use register/unregister functionality for PDISPLAY ISR

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv50_gpio.c b/drivers/gpu/drm/nouveau/nv50_gpio.c
index 302f7eb..87266d1 100644
--- a/drivers/gpu/drm/nouveau/nv50_gpio.c
+++ b/drivers/gpu/drm/nouveau/nv50_gpio.c
@@ -26,6 +26,8 @@
 #include "nouveau_drv.h"
 #include "nouveau_hw.h"
 
+#include "nv50_display.h"
+
 static void nv50_gpio_isr(struct drm_device *dev);
 
 static int
@@ -109,6 +111,8 @@
 		nv_wr32(dev, 0xe074, 0xffffffff);
 	}
 
+	INIT_WORK(&dev_priv->hpd_work, nv50_display_irq_hotplug_bh);
+	spin_lock_init(&dev_priv->hpd_state.lock);
 	nouveau_irq_register(dev, 21, nv50_gpio_isr);
 	return 0;
 }