arm64/mm: Drop idmap_pg_end[] declaration

arm64/mm: Drop idmap_pg_end[] declaration

idmap_pg_end[] is not used anywhere, hence just drop its declaration.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20221116084302.320685-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>