media: mediatek: vcodec: fix AV1 decode fail for 36bit iova

Fix av1 decode fail when iova is 36bit.

Decoder hardware will access incorrect iova address when tile buffer is
36bit, it will lead to iommu fault when hardware access dram data.

Fixes: 2f5d0aef

 ("media: mediatek: vcodec: support stateless AV1 decoder")
Signed-off-by: Xiaoyong <Lu&lt;xiaoyong.lu@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>