drm/i915/documentation: Add intel_uncore.c to drm.tmpl

Include intel_uncore.c in template for it to include d
documentation for intel_uncore_forcewake_get and *_put.

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>