arm64/mm: Drop SWAPPER_INIT_MAP_SIZE

The commit cdef5f6e ("arm64: mm: allocate pagetables anywhere") had
dropped the last reference to SWAPPER_INIT_MAP_SIZE. Hence just clean up.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/1623665411-20055-1-git-send-email-anshuman.khandual@arm.com


Signed-off-by: Will Deacon <will@kernel.org>