LSIO subsystem contains 14 MU instances.

5 MUs to communicate between AP <-> SCU
  - side-A PD range managed by AP
  - side-B PD range managed by SCU

9 MUs to communicate between all cores (AP/M4/DSP).
  - side-A PD range managed by core-A (AP/M4/DSP)
  - side-B PD range managed by core-B (AP/M4/DSP).

Communication between AP <-> DSP is done through the
assigned MU number 13.

So, we power up side-A by the AP and we decide to
power up side-B also from AP. This is because powering
it up from DSP would be painful.

Powering up side B from DSP would require the DSP to
communicate with SCU and to keep things simple we don't
want that now.
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>