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/pico-hobbit-imx6ul_defconfig b/configs/pico-hobbit-imx6ul_defconfig
index 55f25d5..7395598 100644
--- a/configs/pico-hobbit-imx6ul_defconfig
+++ b/configs/pico-hobbit-imx6ul_defconfig
@@ -46,7 +46,7 @@
 CONFIG_DM_I2C=y
 CONFIG_DM_MMC=y
 CONFIG_SUPPORT_EMMC_BOOT=y
-CONFIG_FSL_ESDHC_IMX=y
+CONFIG_FSL_USDHC=y
 CONFIG_PHYLIB=y
 CONFIG_PHY_MICREL=y
 CONFIG_PHY_MICREL_KSZ8XXX=y