disk: convert CONFIG_ISO_PARTITION to Kconfig

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay73@gmail.com>
diff --git a/configs/am43xx_evm_ethboot_defconfig b/configs/am43xx_evm_ethboot_defconfig
index e74e967..f057cf3 100644
--- a/configs/am43xx_evm_ethboot_defconfig
+++ b/configs/am43xx_evm_ethboot_defconfig
@@ -32,6 +32,7 @@
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
+CONFIG_ISO_PARTITION=y
 CONFIG_DFU_MMC=y
 CONFIG_DFU_RAM=y
 CONFIG_DFU_SF=y