drm/radeon/kms/evergreen: add hpd support

Hot plug detect (hpd) for digital monitors

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index e0132ef0..815df34 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -1345,7 +1345,8 @@
 
 extern void r700_cp_stop(struct radeon_device *rdev);
 extern void r700_cp_fini(struct radeon_device *rdev);
-void evergreen_disable_interrupt_state(struct radeon_device *rdev);
+extern void evergreen_disable_interrupt_state(struct radeon_device *rdev);
+extern int evergreen_irq_set(struct radeon_device *rdev);
 
 /* evergreen */
 struct evergreen_mc_save {