imx: add cpu-freq SIP runtime service support

On i.MX8QM/i.MX8QX with system controller inside, the CPU's clock
rate is managed by SCFW(system controller firmware) and can ONLY be
changed from secure world, so SIP runtime service is needed for
setting CPU's clock rate, this patch adds cpu-freq SIP runtime service
support.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
3 files changed