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/mixtile_loftq_defconfig b/configs/mixtile_loftq_defconfig
index b321462..96377d9 100644
--- a/configs/mixtile_loftq_defconfig
+++ b/configs/mixtile_loftq_defconfig
@@ -13,6 +13,7 @@
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_FPGA is not set
 # CONFIG_SPL_DOS_PARTITION is not set
+# CONFIG_SPL_ISO_PARTITION is not set
 CONFIG_ETH_DESIGNWARE=y
 CONFIG_AXP_ALDO1_VOLT=3300
 CONFIG_USB_EHCI_HCD=y