clk: imx: imx8mp: change the 'nand_usdhc_bus' clock to non-critical

The 'nand_usdhc_bus' clock is only need to be enabled when usdhc
or nand module is active, so change it to non-critical clock type.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20230403094633.3366446-4-peng.fan@oss.nxp.com


Signed-off-by: Abel Vesa <abel.vesa@linaro.org>