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/yellowstone_defconfig b/configs/yellowstone_defconfig
index 53d1007..0b08b7d 100644
--- a/configs/yellowstone_defconfig
+++ b/configs/yellowstone_defconfig
@@ -19,6 +19,7 @@
 CONFIG_CMD_CACHE=y
 CONFIG_MAC_PARTITION=y
 CONFIG_DOS_PARTITION=y
+CONFIG_ISO_PARTITION=y
 # CONFIG_PCI_PNP is not set
 CONFIG_SYS_NS16550=y
 CONFIG_OF_LIBFDT=y