drm/i915: Extract engine fault reset to a helper

Just tidying the flow a bit.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190607082557.31670-4-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -1160,6 +1160,12 @@ static void clear_register(struct intel_uncore *uncore, i915_reg_t reg)
 	intel_uncore_rmw(uncore, reg, 0, 0);
 }
 
+static void gen8_clear_engine_error_register(struct intel_engine_cs *engine)
+{
+	GEN6_RING_FAULT_REG_RMW(engine, RING_FAULT_VALID, 0);
+	GEN6_RING_FAULT_REG_POSTING_READ(engine);
+}
+
 void i915_clear_error_registers(struct drm_i915_private *i915,
 				intel_engine_mask_t engine_mask)
 {
@@ -1194,10 +1200,8 @@ void i915_clear_error_registers(struct drm_i915_private *i915,
 		struct intel_engine_cs *engine;
 		enum intel_engine_id id;
 
-		for_each_engine_masked(engine, i915, engine_mask, id) {
-			GEN6_RING_FAULT_REG_RMW(engine, RING_FAULT_VALID, 0);
-			GEN6_RING_FAULT_REG_POSTING_READ(engine);
-		}
+		for_each_engine_masked(engine, i915, engine_mask, id)
+			gen8_clear_engine_error_register(engine);
 	}
 }