drm/vc4: Fix memory leak during BO teardown

During BO teardown, an indirect list 'uniform_addr_offsets' wasn't being
freed leading to leaking many 128B allocations. Fix the memory leak by
releasing it at teardown time.

Cc: stable@vger.kernel.org
Fixes: 6d45c81d

 ("drm/vc4: Add support for branching in shader validation.")
Signed-off-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180402071035.25356-1-daniel@quora.org