drm/i915: Stop inlining the execlists IRQ handler

As the handler is now quite complex, involving a few atomics, the cost
of the function preamble is negligible in comparison and so we should
leave the function out-of-line for better I$.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-11-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_irq.c

@@ -1353,7 +1353,7 @@ static void snb_gt_irq_handler(struct drm_i915_private *dev_priv,
 		ivybridge_parity_error_irq_handler(dev_priv, gt_iir);
 }
 
-static __always_inline void
+static void
 gen8_cs_irq_handler(struct intel_engine_cs *engine, u32 iir, int test_shift)
 {
 	bool tasklet = false;