drm/i915: Fix kerneldoc warnings for i915_gem_internal

drivers/gpu/drm/i915/i915_gem_internal.c:183: warning: No description found for parameter 'i915'
drivers/gpu/drm/i915/i915_gem_internal.c:183: warning: No description found for parameter 'size'

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208114224.27271-1-chris@chris-wilson.co.uk


Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>