SNVS powerkey driver needs snvs clock for proper clock management,
add support for it.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>