mmc: fsl_esdhc_imx: replace all readl/writel to esdhc_read32/esdhc_write32

Currently, readl/writel and esdhc_read32/esdhc_write32 are used. To align
the usage, change to only use esdhc_read32/esdhc_write32.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>