iommu/amd: Introduce iommu_dev_data.max_pasids

iommu/amd: Introduce iommu_dev_data.max_pasids

This variable will track the number of PASIDs supported by the device.
If IOMMU or device doesn't support PASID then it will be zero.

This will be used while allocating GCR3 table to decide required number
of PASID table levels. Also in PASID bind path it will use this variable
to check whether device supports PASID or not.

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240418103400.6229-7-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>