memblock: Track total size of regions automatically

Total size of memory regions was calculated by memblock_analyze()
requiring explicitly calling the function between operations which can
change memory regions and possible users of total size, which is
cumbersome and fragile.

This patch makes each memblock_type track total size automatically
with minor modifications to memblock manipulation functions and remove
requirements on calling memblock_analyze().  [__]memblock_dump_all()
now also dumps the total size of reserved regions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Yinghai Lu <yinghai@kernel.org>