mmc: sdhci-esdhc-imx: Move mmc_of_parse() to the dt probe

mmc_of_parse() should be placed inside sdhci_esdhc_imx_probe_dt() as it
suits only for the dt case.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>