mmc: fsl_esdhc_imx: Implement wait_dat0 mmc ops

mmc: fsl_esdhc_imx: Implement wait_dat0 mmc ops

Implement wait_dat0 mmc ops callbac, allowing to reduce SPL boot time.

Before (using grabserial):
[0.000001 0.000001] U-Boot SPL 2021.04-xxxx
[0.028257 0.028257] DDRINFO: start DRAM init
[0.028500 0.000243] DDRINFO: DRAM rate 3000MTS
[0.304627 0.276127] DDRINFO:ddrphy calibration done
[0.305647 0.001020] DDRINFO: ddrmix config done
[0.352584 0.046937] SEC0:  RNG instantiated
[0.374299 0.021715] Normal Boot
[0.374675 0.000376] Trying to boot from MMC2
[1.250580 0.875905] NOTICE:  BL31: v2.4(release):lf-5.10.72-2.2.0-0-g5782363f9
[1.251985 0.001405] NOTICE:  BL31: Built : 08:02:40, Apr 12 2022
[1.522560 0.270575]
[1.522734 0.000174]
[1.522788 0.000054] U-Boot 2021.04-xxxx

After:
[0.000001 0.000001] U-Boot SPL 2021.04-xxxx
[0.001614 0.001614] DDRINFO: start DRAM init
[0.002377 0.000763] DDRINFO: DRAM rate 3000MTS
[0.278494 0.276117] DDRINFO:ddrphy calibration done
[0.279266 0.000772] DDRINFO: ddrmix config done
[0.338432 0.059166] SEC0:  RNG instantiated
[0.339051 0.000619] Normal Boot
[0.339431 0.000380] Trying to boot from MMC2
[0.412587 0.073156] NOTICE:  BL31: v2.4(release):lf-5.15.5-1.0.0-0-g05f788b
[0.414191 0.001604] NOTICE:  BL31: Built : 10:35:26, Apr  6 2022
[0.700685 0.286494]
[0.700793 0.000108]
[0.700845 0.000052] U-Boot 2021.04-xxxx

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>