iommu/amd: Fix PASID format in INVALIDATE_IOTLB_PAGES command

This patch corrects the PASID format in the INVALIDATE_IOTLB_PAGES
command, which was caused by incorrect information in
the AMD IOMMU Architectural Specification v2.01 document.

    Incorrect format:
         cmd->data[0][16:23] = PASID[7:0]
         cmd->data[1][16:27] = PASID[19:8]

     Correct format:
         cmd->data[0][16:23] = PASID[15:8]
         cmd->data[1][16:23] = PASID[7:0]

However, this does not affect the IOMMUv2 hardware implementation,
and has been corrected since version 2.02 of the specification
(available through AMD NDA).

Signed-off-by: Jay Cornwall <jay.cornwall@amd.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>