treewide: Migrate CONFIG_FSL_ESDHC to Kconfig

Migrate the CONFIG_FSL_ESDHC option to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/imx6ul_isiot_nand_defconfig b/configs/imx6ul_isiot_nand_defconfig
index 7f47230..2c84424 100644
--- a/configs/imx6ul_isiot_nand_defconfig
+++ b/configs/imx6ul_isiot_nand_defconfig
@@ -36,6 +36,7 @@
 CONFIG_CMD_UBI=y
 CONFIG_ENV_IS_IN_NAND=y
 CONFIG_SYS_I2C_MXC=y
+CONFIG_FSL_ESDHC=y
 CONFIG_NAND=y
 CONFIG_NAND_MXS=y
 CONFIG_PHYLIB=y