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/cl-som-am57x_defconfig b/configs/cl-som-am57x_defconfig
index 6711075..cbdca06 100644
--- a/configs/cl-som-am57x_defconfig
+++ b/configs/cl-som-am57x_defconfig
@@ -23,6 +23,7 @@
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
+CONFIG_ISO_PARTITION=y
 CONFIG_LED_STATUS=y
 CONFIG_LED_STATUS_GPIO=y
 CONFIG_LED_STATUS0=y