drm/doc: Fixup drm_irq kerneldoc includes.

Only !P can be used together with a function list.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Documentation/DocBook/drm.tmpl

@@ -3406,7 +3406,7 @@ void (*disable_vblank) (struct drm_device *dev, int crtc);</synopsis>
     <sect2>
       <title>Vertical Blanking and Interrupt Handling Functions Reference</title>
 !Edrivers/gpu/drm/drm_irq.c
-!Iinclude/drm/drmP.h drm_crtc_vblank_waitqueue
+!Finclude/drm/drmP.h drm_crtc_vblank_waitqueue
     </sect2>
   </sect1>