minigbm: remove BO_USE_RENDERING from certain formats

minigbm: remove BO_USE_RENDERING from certain formats

We can't use GR88, R8, YV12, NV12, UYVY, YUYV buffers as render
targets, so let's remove the BO_USE_RENDERING flag from these
formats. However, we can sample from these formats (though this
feature still needs to be enabled in our drivers), so the
BO_USE_TEXTURE flag remains set.

Also, change our interpretation of the GRALLOC_USAGE_HW_COMPOSER
flag such that it implies BO_USE_SCANOUT | BO_USE_TEXTURE. This
is because the OpenGL fallback textures from the buffer if
can't be scanned-out, not renders to it.

BUG=none
TEST=run Youtube app on Kevin

Change-Id: I9ea8452279e110bc1a9579f162abe1c72192eb40
Reviewed-on: https://chromium-review.googlesource.com/506812
Commit-Ready: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>