clk: imx: Pass struct udevice into imx_clk_mux*()

clk: imx: Pass struct udevice into imx_clk_mux*()

Pass struct udevice * into imx_clk_mux*() functions, so the
clock core would have access to parent struct udevice *.

Signed-off-by: Marek Vasut <marex@denx.de>