drm/i915: remove duplicate definition of for_each_power_domain

commit b04c5bd6fda54703e56f29569e4bca489d6c5a5c
Author: Borun Fu <borun.fu@intel.com>
Date:   Sat Jul 12 10:02:27 2014 +0530

    drm/i915: Power gating display wells during i915_pm_suspend

moved for_each_power_domain from intel_display.c to i915_drv.h but we
still have the definition around in intel_display.c, due to a merge
conflict resolution gone wrong in

commit 4dac3edfe68e5e1b3c2216b84ba160572420fa40
Merge: 487777673e35 e05444be705b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Jul 29 20:49:36 2014 +0200

    Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next

Just remove the extra definition left behind.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448383645-7615-1-git-send-email-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -5232,10 +5232,6 @@ static enum intel_display_power_domain port_to_aux_power_domain(enum port port)
 	}
 }
 
-#define for_each_power_domain(domain, mask)				\
-	for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++)	\
-		if ((1 << (domain)) & (mask))
-
 enum intel_display_power_domain
 intel_display_port_power_domain(struct intel_encoder *intel_encoder)
 {