Add support for Xiaomi Mi Pad 5 Pro, codename is xiaomi-elish.

This commit brings support for:
  * ADSP/CDSP/SLPI/VENUS
  * Backlight
  * Battery fuel gauge
  * Framebuffer
  * PCIe0
  * USB2.0
Signed-off-by: Jianhua Lu <lujianhua000@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230131123515.833-2-lujianhua000@gmail.com