Multiple CPU clusters are used in Hisilicon HiP04 SoC. Now use MCPM
framework to manage power on HiP04 SoC.

Changelog:
v20:
  * Disable L2 prefetch when the whole cluster is down.
  * Move disabling snoop filter into power_down() after L2 prefetch
    disabled.
  * Remove delay in wait_for_power_down() after L2 prefetch disabled.
  * Add the sleep polling in wait_for_power_down() again since we
    need to wait L2 when the cluster is down.
v19:
  * Add comments on those delay hacks.
  * Update on checking core enabled counts in wait_for_power_down().
v18:
  * Fix to release resource in probe().
  * Check whether cpu is already up in the process of making cpu down.
  * Add udelay in power up/down sequence.
  * Optimize on setting relocation entry.
  * Optimize on polling status in wait_for_power_down().
  * Add mcpm critical operations.
v17:
  * Parse bootwrapper parameters in DTS file.
  * Fix to use msleep() in spinlock region.
v16:
  * Parse bootwrapper parameters in command line instead.
v13:
  * Restore power down operation in MCPM.
  * Fix disabling snoop filter issue in MCPM.
v12:
  * Use wfi as power down state in MCPM.
  * Remove wait_for_powerdown() in MCPM because wfi is used now.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>