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/orangepi_pc_plus_defconfig b/configs/orangepi_pc_plus_defconfig
index e19fdef..cee8085 100644
--- a/configs/orangepi_pc_plus_defconfig
+++ b/configs/orangepi_pc_plus_defconfig
@@ -14,6 +14,7 @@
 # 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_SUN8I_EMAC=y
 CONFIG_SY8106A_POWER=y
 CONFIG_USB_EHCI_HCD=y