media: videobuf2: rework vb2_mem_ops API

With the new DMA API we need an extension of the videobuf2 API.
Previously, videobuf2 core would set the non-coherent DMA bit
in the vb2_queue dma_attr field (if user-space would pass a
corresponding memory hint); the vb2 core then would pass the
vb2_queue dma_attrs to the vb2 allocators. The vb2 allocator
would use the queue's dma_attr and the DMA API would allocate
either coherent or non-coherent memory.

But we cannot do this anymore, since there is no corresponding DMA
attr flag and, hence, there is no way for the allocator to become
aware of what type of allocation user-space has requested. So we
need to pass more context from videobuf2 core to the allocators.

Fix this by changing the call_ptr_memop() macro to pass the
vb2 pointer to the corresponding op callbacks.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>