arm64: hugetlb: Override set_huge_swap_pte_at() to support contiguous hugepages

The default implementation of set_huge_swap_pte_at() does not support
hugepages consisting of contiguous ptes. Override it to add support for
contiguous hugepages.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Cc: David Woods <dwoods@mellanox.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>