iommu/amd: Move PPR-related functions into ppr.c

iommu/amd: Move PPR-related functions into ppr.c

In preparation to subsequent PPR-related patches, and also remove static
declaration for certain helper functions so that it can be reused in other
files.

Also rename below functions:
  alloc_ppr_log        -> amd_iommu_alloc_ppr_log
  iommu_enable_ppr_log -> amd_iommu_enable_ppr_log
  free_ppr_log         -> amd_iommu_free_ppr_log
  iommu_poll_ppr_log   -> amd_iommu_poll_ppr_log

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/20240418103400.6229-5-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>