genpd: imx: scu-pd: initialize is_off according to HW state

The current code default set is_off to true except console resource,
this implies bootloader should power off all the resources it uses.

But this is not always true, let's check the HW state and set is_off.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>