drm/i915/bdw+: Move misc display IRQ handling to it own function

Just moving it to reduce the tabs and avoid break code lines.
No behavior changes intended here.

v2:
- Reading misc display IRQ outside of gen8_de_misc_irq_handler() as
other irq handlers (Dhinakaran)

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730224753.14907-1-jose.souza@intel.com

drivers/gpu/drm/i915/i915_irq.c

@@ -2644,21 +2644,11 @@ static u32 gen8_de_pipe_fault_mask(struct drm_i915_private *dev_priv)
 		return GEN8_DE_PIPE_IRQ_FAULT_ERRORS;
 }
 
-static irqreturn_t
-gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
+static void
+gen8_de_misc_irq_handler(struct drm_i915_private *dev_priv, u32 iir)
 {
-	irqreturn_t ret = IRQ_NONE;
-	u32 iir;
-	enum pipe pipe;
-
-	if (master_ctl & GEN8_DE_MISC_IRQ) {
-		iir = I915_READ(GEN8_DE_MISC_IIR);
-		if (iir) {
 	bool found = false;
 
-			I915_WRITE(GEN8_DE_MISC_IIR, iir);
-			ret = IRQ_HANDLED;
-
 	if (iir & GEN8_DE_MISC_GSE) {
 		intel_opregion_asle_intr(dev_priv);
 		found = true;
@@ -2674,10 +2664,25 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
 
 	if (!found)
 		DRM_ERROR("Unexpected DE Misc interrupt\n");
-		}
-		else
+}
+
+static irqreturn_t
+gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
+{
+	irqreturn_t ret = IRQ_NONE;
+	u32 iir;
+	enum pipe pipe;
+
+	if (master_ctl & GEN8_DE_MISC_IRQ) {
+		iir = I915_READ(GEN8_DE_MISC_IIR);
+		if (iir) {
+			I915_WRITE(GEN8_DE_MISC_IIR, iir);
+			ret = IRQ_HANDLED;
+			gen8_de_misc_irq_handler(dev_priv, iir);
+		} else {
 			DRM_ERROR("The master control interrupt lied (DE MISC)!\n");
 		}
+	}
 
 	if (INTEL_GEN(dev_priv) >= 11 && (master_ctl & GEN11_DE_HPD_IRQ)) {
 		iir = I915_READ(GEN11_DE_HPD_IIR);