iommu/amd: Refactor helper function for setting / clearing GCR3

Refactor GCR3 helper functions in preparation to use per device
GCR3 table.
  * Add new function update_gcr3 to update per device GCR3 table

  * Remove per domain default GCR3 setup during v2 page table allocation.
    Subsequent patch will add support to setup default gcr3 while
    attaching device to domain.

  * Remove amd_iommu_domain_update() from V2 page table path as device
    detach path will take care of updating the domain.

  * Consolidate GCR3 table related code in one place so that its easy
    to maintain.

  * Rename functions to reflect its usage.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240205115615.6053-11-vasant.hegde@amd.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>