功能描述：
  在proc目录下增加power目录，添加powr_mode,power_lock,power_unlock和power_count节点，
  power_mode：节点用于查询和设置系统支持的功耗模式
  power_lock：用于查询和获取低功耗锁，持锁后，将会阻止系统进入低功耗状态
  power_unlock:　用于释放已经持有的低功耗锁，也可查询当前有那些持有低功耗锁
  power_count：用于查询当前持有低功耗锁的个数

Close #I3VS5N

Change-Id: I2e2881cc968eab3c5fa6f9dbd7e8c5e448609407
Signed-off-by: Nzhushengle <zhushengle@huawei.com>

1, this RomFS's codebase is Nuttx romfs, then it is compatible with
Linux RomFS and you can create such a file system using the tool genromfs.
2, there are two major changes against with the original Nuttx romfs:
    1), it is memory-based: all contents of the fs are stored in the
        memory in the very first stage of "mount".
    2), this version of romfs is altered to be compatible with our new
        version of VFS to take advantage of vnode cache and path cache.

close: #I3S0CP

close: #I3T5HR
Change-Id: I2e2452d59c82726614fb78d1177d3f0f03d6e315
Signed-off-by: Narvinzzz <fcykztyu@163.com>

Change-Id: I7f0b44c15a296bd8d15f0bf1fbdde60f67bb0a6c

close: #I3I768

Change-Id: I4f801df4abe1a9afdf43391c28276e96a5e81513

Change-Id: I052d930d54e63179b17b77f02c107a015f3cfc3f

Change-Id: Ia6c1f6302407a707b3ec9b805f4c92d8a7970b86