drm/i915: Use proper fault mask in interrupt postinstall too

The IRQ postinstall handling had open-coded pipe fault mask selection
that never got updated for gen11.  Switch it to use
gen8_de_pipe_fault_mask() to ensure we don't miss updates for new
platforms.

Cc: José Roberto de Souza <jose.souza@intel.com>
Fixes: d506a65 ("drm/i915: Catch GTT fault errors for gen11+ planes")
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200424231423.4065231-1-matthew.d.roper@intel.com
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/i915_irq.c

@@ -3358,7 +3358,8 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 {
 	struct intel_uncore *uncore = &dev_priv->uncore;
 
-	u32 de_pipe_masked = GEN8_PIPE_CDCLK_CRC_DONE;
+	u32 de_pipe_masked = gen8_de_pipe_fault_mask(dev_priv) |
+		GEN8_PIPE_CDCLK_CRC_DONE;
 	u32 de_pipe_enables;
 	u32 de_port_masked = GEN8_AUX_CHANNEL_A;
 	u32 de_port_enables;
@@ -3369,13 +3370,10 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 		de_misc_masked |= GEN8_DE_MISC_GSE;
 
 	if (INTEL_GEN(dev_priv) >= 9) {
-		de_pipe_masked |= GEN9_DE_PIPE_IRQ_FAULT_ERRORS;
 		de_port_masked |= GEN9_AUX_CHANNEL_B | GEN9_AUX_CHANNEL_C |
 				  GEN9_AUX_CHANNEL_D;
 		if (IS_GEN9_LP(dev_priv))
 			de_port_masked |= BXT_DE_PORT_GMBUS;
-	} else {
-		de_pipe_masked |= GEN8_DE_PIPE_IRQ_FAULT_ERRORS;
 	}
 
 	if (INTEL_GEN(dev_priv) >= 11)