mm: export node type {pmem|dram} under /sys/bus/node

euleros inclusion
category: feature
feature: etmem
bugzilla: https://gitee.com/openeuler/kernel/issues/I4OODH?from=project-issue


CVE: NA

-------------------------------------------------

User space migration daemon could check
/sys/bus/node/devices/nodeX/type for node type.

Software can interrogate node type for node memory type and distance
to get desirable target node in migration.

grep -r . /sys/devices/system/node/*/type
/sys/devices/system/node/node0/type:dram
/sys/devices/system/node/node1/type:dram
/sys/devices/system/node/node2/type:pmem
/sys/devices/system/node/node3/type:pmem

Along with next patch which export `peer_node`, migration daemon
could easily find the memory type of current node, and the target
node in case of migration.

grep -r . /sys/devices/system/node/*/peer_node
/sys/devices/system/node/node0/peer_node:2
/sys/devices/system/node/node1/peer_node:3
/sys/devices/system/node/node2/peer_node:0
/sys/devices/system/node/node3/peer_node:1

Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Reviewed-by: louhongxiang <louhongxiang@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>