uboot-imx

MLK-21848-5 fsl_esdhc: fix problem when using clk driver

Should use CONFIG_IS_ENABLED not IS_ENABLED for CLK driver, so it will
check the CONFIG_SPL_CLK when building SPL

Move init_clk_usdhc to non-clk driver case, since assigned-clocks properties
will initialize the clocks by clk driver.

Signed-off-by: Ye Li <ye.li@nxp.com>