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/pico-imx6ul_defconfig b/configs/pico-imx6ul_defconfig
index c6fa11a..67b3eb1 100644
--- a/configs/pico-imx6ul_defconfig
+++ b/configs/pico-imx6ul_defconfig
@@ -30,6 +30,7 @@
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_DFU_MMC=y
+CONFIG_FSL_ESDHC=y
 CONFIG_PHYLIB=y
 CONFIG_PHY_MICREL=y
 CONFIG_USB=y