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/vct_platinum_onenand_small_defconfig b/configs/vct_platinum_onenand_small_defconfig
index 50d2619..0e4964b 100644
--- a/configs/vct_platinum_onenand_small_defconfig
+++ b/configs/vct_platinum_onenand_small_defconfig
@@ -21,4 +21,5 @@
 # CONFIG_CMD_NFS is not set
 # CONFIG_CMD_MISC is not set
 CONFIG_CMD_UBI=y
+# CONFIG_ISO_PARTITION is not set
 CONFIG_SYS_NS16550=y