ARM: 9255/1: efi/dump UEFI runtime page tables for ARM

ARM: 9255/1: efi/dump UEFI runtime page tables for ARM

UEFI runtime page tables dump only for ARM64 at present,
but ARM support EFI and ARM_PTDUMP_DEBUGFS now. Since
ARM could potentially execute with a 1G/3G user/kernel
split, choosing 1G as the upper limit for UEFI runtime
end, with this, we could enable UEFI runtime page tables
on ARM.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>