mmc: sdhci-esdhc-imx: Select the correct mode for auto tuning

USDHC hardware auto tuning circuit support check 1/4/8 data lines and cmd
line. Out of reset uSDHC, it default select check 4 data lines and do not
check cmd line. This is incorrect if we use 8 data lines. So need to config
the auto tuning mode according to current bus width.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://lore.kernel.org/r/1629285415-7495-2-git-send-email-haibo.chen@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>