MLK-16118-8 imx8qm/qxp: Enable the power domain driver and update relevant codes

MLK-16118-8 imx8qm/qxp: Enable the power domain driver and update relevant codes

This patch enables the power domain driver for i.MX8QM and QXP boards in defconfig files.
The devices with using DM driver will be powered on automatically by DM framework. So
we remove the power relevant codes for them.
For devices with non-DM drivers, we updates the board/SoC codes to use power domain driver API.
So that we can use power domain driver to manage them.

The only exceptions are:
1. UART0 at board_early_f, this is very early stage, that power domain is not ready.
2. Power up secondary cores and M4 cores. These resources are not peripherals and
   are not in power domain tree.

Additional, benefiting from power domain driver, We have implemented the function "power_off_pd_devices"
to power off all active devices. No need to explicitly power off them in board_quiesce_devices.

Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>