imx8m: add clk support for i.MX8MN

i.MX8MN has similar architecture with i.MX8MM, so it could reuse
the clock code of i.MX8MM, but i.MX8MN has different CCM root
configurations, so need a separate root entry.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
4 files changed