virtgpu: always make it mappable for GPU_DATA_BUFFER

Venus device memory mapping setup must succeed for AHB VkBuffer.
Meanwhile, the imported AHB can be allocated with only GPU_DATA_BUFFER
flag. So we must add mappable flag in virtgpu backends accordingly.

BUG=b:246814802
TEST=Blob_BlobTest_GpuDataBufferVertexBuffer_BLOB

Change-Id: I88f63c732d3b133daf755d73ed54578605d27112
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/3896159
Tested-by: Yiwei Zhang <zzyiwei@chromium.org>
Reviewed-by: Chia-I Wu <olv@google.com>
Commit-Queue: Yiwei Zhang <zzyiwei@chromium.org>
Reviewed-by: Rob Clark <robdclark@chromium.org>
2 files changed