dt-bindings: media: venus: Fix iommus property

dt-bindings: media: venus: Fix iommus property

Fix IOMMU DT propety for venus via dropping SMMU stream IDs which
relates to secure context bank. Assigning Linux kernel (HLOS) VMID
to secure context bank stream IDs is incorrect. The maximum value
for iommus property is updated accordingly.

These DT bindings changes should be backwards compatible.

Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20260122121042.579270-3-sumit.garg@kernel.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>