drm/i915: Remove bogus kerneldoc include directive

Afaict intel_irq_fini never existed. No idea how that one came
about.

Note: Chris thinks that an irq_fini would be nice and I agree, but
this is just to remove some ugly from generated docs.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Documentation/DocBook/drm.tmpl

@@ -3982,7 +3982,6 @@ int num_ioctls;</synopsis>
         <title>Interrupt Handling</title>
 !Pdrivers/gpu/drm/i915/i915_irq.c interrupt handling
 !Fdrivers/gpu/drm/i915/i915_irq.c intel_irq_init intel_irq_init_hw intel_hpd_init
-!Fdrivers/gpu/drm/i915/i915_irq.c intel_irq_fini
 !Fdrivers/gpu/drm/i915/i915_irq.c intel_runtime_pm_disable_interrupts
 !Fdrivers/gpu/drm/i915/i915_irq.c intel_runtime_pm_enable_interrupts
       </sect2>