drm/i915: Fold IRQ pipe masks

Fold IRQ pipe masks into one loop instead of hardcoding per pipe.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kahola <mika.kahola@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1507630626-23806-4-git-send-email-mika.kahola@intel.com

drivers/gpu/drm/i915/i915_irq.c

@@ -3610,16 +3610,15 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 	else if (IS_BROADWELL(dev_priv))
 		de_port_enables |= GEN8_PORT_DP_A_HOTPLUG;
 
-	dev_priv->de_irq_mask[PIPE_A] = ~de_pipe_masked;
-	dev_priv->de_irq_mask[PIPE_B] = ~de_pipe_masked;
-	dev_priv->de_irq_mask[PIPE_C] = ~de_pipe_masked;
+	for_each_pipe(dev_priv, pipe) {
+		dev_priv->de_irq_mask[pipe] = ~de_pipe_masked;
 
-	for_each_pipe(dev_priv, pipe)
 		if (intel_display_power_is_enabled(dev_priv,
 				POWER_DOMAIN_PIPE(pipe)))
 			GEN8_IRQ_INIT_NDX(DE_PIPE, pipe,
 					  dev_priv->de_irq_mask[pipe],
 					  de_pipe_enables);
+	}
 
 	GEN3_IRQ_INIT(GEN8_DE_PORT_, ~de_port_masked, de_port_enables);
 	GEN3_IRQ_INIT(GEN8_DE_MISC_, ~de_misc_masked, de_misc_masked);