x86: merge zones_sizes_init for numa and non numa on 32-bit

move out e820_register_active_regions from non numa zones_sizes_init()
and remove numa version zones_sizes_init().

and let 32 bit call remove_all_active_ranges() in setup_arch() directly
like 64-bit

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>