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/mx6ull_14x14_evk_defconfig b/configs/mx6ull_14x14_evk_defconfig
index 375db54..1172f41 100644
--- a/configs/mx6ull_14x14_evk_defconfig
+++ b/configs/mx6ull_14x14_evk_defconfig
@@ -27,6 +27,7 @@
 CONFIG_DM_74X164=y
 CONFIG_DM_I2C=y
 CONFIG_DM_MMC=y
+CONFIG_FSL_ESDHC=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_BAR=y