arm64, NUMA: rework numa_add_memblk()

Rework numa_add_memblk() to update the parameter "u64 size" to "u64
end", this will make it consistent with x86 and simplifies the arm64
ACPI NUMA code to be added later.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>