x86, memblock: Add memblock_x86_reserve_range/memblock_x86_free_range

x86, memblock: Add memblock_x86_reserve_range/memblock_x86_free_range

They are wrappers for core versions, which take start/end/name instead
of base/size.  This will make x86 conversion eaasier.

could add more debug print out

-v2: change get_max_mapped() to memblock.default_alloc_limit according to Michael
      Ellerman and Ben
     change to memblock_x86_reserve_range and memblock_x86_free_range according to Michael Ellerman
-v3: call check_and_double after reserve/free, so could avoid to use
      find_memblock_area. Suggested by Michael Ellerman

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>