drm/radeon/kms: Fix irq handling on AVIVO hw

Avivo hw have vblank interrupt in different place, fixes
irq handling (especialy irq disabling while suspending or
shuting down the module).

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r520.c b/drivers/gpu/drm/radeon/r520.c
index a58b6fa..a555b7b 100644
--- a/drivers/gpu/drm/radeon/r520.c
+++ b/drivers/gpu/drm/radeon/r520.c
@@ -186,7 +186,7 @@
 	}
 	/* Enable IRQ */
 	rdev->irq.sw_int = true;
-	r100_irq_set(rdev);
+	rs600_irq_set(rdev);
 	/* 1M ring buffer */
 	r = r100_cp_init(rdev, 1024 * 1024);
 	if (r) {