clk: imx: imx8mq: Switch to clk_hw based API

Switch the entire clk-imx8mq driver to clk_hw based API.
This allows us to move closer to a clear split between
consumer and provider clk APIs.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>