drm/i915: group link_standby setup and let this info visible everywhere.

No functional changes on this patch. Just grouping the link_standy decision
to avoid miss any change. Also making this info available everywhere
which will help to decide when to use vbt's tp time on following patch.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Durgadoss R <durgadoss.r@intel.com>
[danvet: Slight editing of the commit message which was one huge
run-on sentence.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 66f0c60..aeb1aa7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -789,6 +789,7 @@
 	bool active;
 	struct delayed_work work;
 	unsigned busy_frontbuffer_bits;
+	bool link_standby;
 };
 
 enum intel_pch {