media: rkvdec: Restore iommu addresses on errors

On errors, the rkvdec chip self resets. This can clear the addresses
programmed in the iommu. This case is signaled by the
RKVDEC_SOFTRESET_RDY status bit.

Since the iommu framework does not have a restore functionality, and
as recommended by the iommu subsystem maintainers, this patch
restores the iommu programming by attaching an empty domain, detaching
it and re-attaching the device allocated domain.

Suggested-by: Detlev Casanova <detlev.casanova@collabora.com>
Signed-of-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>