sparc: Use HAVE_MEMBLOCK_NODE_MAP

sparc doesn't access early_node_map[] directly and enabling
HAVE_MEMBLOCK_NODE_MAP is trivial - replacing add_active_range() calls
with memblock_set_node() and selecting HAVE_MEMBLOCK_NODE_MAP is
enough.

-v2: Use select in Kconfig instead as suggested by Sam Ravnborg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: sparclinux@vger.kernel.org