armv8: layerscape: add PSCI support for cpu release

For cpu release command, check whether PSCI is supported firstly,
if supported, use PSCI to kick off secondary cores, otherwise still
use spin table.

Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>
[Fixed checkpatch alignment CHECKs]
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>