feat(plat/nxp/common): define default PSCI features if not defined
feat(plat/nxp/common): define default PSCI features if not defined

SoC code can define supported features, otherwise use default setting.

Signed-off-by: Biwen Li <e4eb6f65ef5d475b9c0f43695faa90378c98910a@nxp.com>
Signed-off-by: Jiafei Pan <9a82dae3c788da2e3e922121e23957d42a7b9dfb@nxp.com>
Change-Id: I0f11498c1f7558ff0ec2d9b344f3f7a4f5489ced

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware