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/warp7_defconfig b/configs/warp7_defconfig
index 29c4512..3901a27 100644
--- a/configs/warp7_defconfig
+++ b/configs/warp7_defconfig
@@ -28,6 +28,7 @@
 CONFIG_CMD_FAT=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_DFU_MMC=y
+CONFIG_FSL_ESDHC=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_MXC_USB_OTG_HACTIVE=y