iommu/amd: Use put_pages_list

iommu/amd: Use put_pages_list

page->freelist is for the use of slab.  We already have the ability
to free a list of pages in the core mm, but it requires the use of a
list_head and for the pages to be chained together through page->lru.
Switch the AMD IOMMU code over to using free_pages_list().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
[rm: split from original patch, cosmetic tweaks]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/73af128f651aaa1f38f69e586c66765a88ad2de0.1639753638.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>