minigbm: rockchip/mediatek: invalidate shadow buffers

In the case where process A is writing to the buffer, and process
B is reading from the buffer via a shadow buffer, we should update
the shadow buffer.

This issue seems to only pop on renderscript tests on Mediatek devices,
but that's due the various differences between 3D driver implementations.
Let's modify rockchip for correctness as well.

BUG=b:69700010
TEST=run cts -m CtsViewTestCases -t android.view.cts.SurfaceViewSyncTests
     passes on Oak

Change-Id: Id551027a2093f5423ee380d8935637d6256d2295
Reviewed-on: https://chromium-review.googlesource.com/795038
Commit-Ready: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
2 files changed