core: arm: imx: Support psci feature query
core: arm: imx: Support psci feature query

Support PSCI call to query features list. So that non-secure world
knows what features are supported by ATF. The feature list is based
on current implemented iMX psci functions.

Signed-off-by: Jun Nie <16d8bc3f29c489fdc436b48884adedee8c6f9a7b@linaro.org>
Acked-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org>
Acked-by: Peng Fan <d3c162a96b7fb54e5d94bc77bc2c7cbbce10806f@nxp.com>

pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os