arm64/mm: enable HugeTLB migration for contiguous bit HugeTLB pages

arm64/mm: enable HugeTLB migration for contiguous bit HugeTLB pages

Let arm64 subscribe to the previously added framework in which
architecture can inform whether a given huge page size is supported for
migration.  This just overrides the default function
arch_hugetlb_migration_supported() and enables migration for all
possible HugeTLB page sizes on arm64.

With this, HugeTLB migration support on arm64 now covers all possible
HugeTLB options.

          CONT PTE    PMD    CONT PMD    PUD
          --------    ---    --------    ---
  4K:        64K      2M        32M      1G
  16K:        2M     32M         1G
  64K:        2M    512M        16G

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Reviewed-by: Steve Capper <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>