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/kp_imx6q_tpc_defconfig b/configs/kp_imx6q_tpc_defconfig
index 87b25e6..578e701 100644
--- a/configs/kp_imx6q_tpc_defconfig
+++ b/configs/kp_imx6q_tpc_defconfig
@@ -34,7 +34,7 @@
 # CONFIG_ISO_PARTITION is not set
 # CONFIG_EFI_PARTITION is not set
 CONFIG_ENV_IS_IN_MMC=y
-CONFIG_FSL_ESDHC_IMX=y
+CONFIG_FSL_USDHC=y
 CONFIG_PHYLIB=y
 CONFIG_PHY_ATHEROS=y
 CONFIG_FEC_MXC=y