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/highbank_defconfig b/configs/highbank_defconfig
index b1c8afd..8fd74ef 100644
--- a/configs/highbank_defconfig
+++ b/configs/highbank_defconfig
@@ -20,4 +20,5 @@
 CONFIG_CMD_EXT4=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
+CONFIG_ISO_PARTITION=y
 CONFIG_OF_LIBFDT=y