mmc: fsl_esdhc_imx: optimize the timing setting

mmc: fsl_esdhc_imx: optimize the timing setting

For imx usdhc/esdhc, once set the DDR_EN, enable the DDR mode, the
card clock will be divied by 2 automatically by the host. So need
to first config the DDR_EN correctly, then update the card clock.
This will make sure the actual card clock is as our expected.
IC also suggest config the DDR_EN firstly, then config the clock
divider.

For HS400/HS400ES mode, need to config the strobe dll, this need
to based on the correct target clock rate, so need to do this after
clock rate is update.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>