Convert CONFIG_FSL_USDHC to Kconfig

This converts the following to Kconfig:
   CONFIG_FSL_USDHC

Signed-off-by: Adam Ford <aford173@gmail.com>
[trini: Add IMX8M, TARGET_S32V234EVB to FSL_USDHC list]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/display5_defconfig b/configs/display5_defconfig
index 2275ee7..3e8f1e9 100644
--- a/configs/display5_defconfig
+++ b/configs/display5_defconfig
@@ -67,7 +67,7 @@
 CONFIG_BOOTCOUNT_LIMIT=y
 CONFIG_BOOTCOUNT_BOOTLIMIT=3
 CONFIG_SUPPORT_EMMC_BOOT=y
-CONFIG_FSL_ESDHC_IMX=y
+CONFIG_FSL_USDHC=y
 CONFIG_MTD_DEVICE=y
 CONFIG_SPI_FLASH=y
 CONFIG_SF_DEFAULT_BUS=1