arm64/mm: enable HugeTLB migration

Let arm64 subscribe to generic HugeTLB page migration framework.  Right
now this only works on the following PMD and PUD level HugeTLB page
sizes with various kernel base page size combinations.

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

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]>

Author: Anshuman Khandual

arch/arm64/Kconfig

@@ -1467,6 +1467,10 @@ config SYSVIPC_COMPAT
 	def_bool y
 	depends on COMPAT && SYSVIPC
 
+config ARCH_ENABLE_HUGEPAGE_MIGRATION
+	def_bool y
+	depends on HUGETLB_PAGE && MIGRATION
+
 menu "Power management options"
 
 source "kernel/power/Kconfig"