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/M54455EVB_defconfig b/configs/M54455EVB_defconfig
index 89150a7..751a059 100644
--- a/configs/M54455EVB_defconfig
+++ b/configs/M54455EVB_defconfig
@@ -16,5 +16,6 @@
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_FAT=y
+CONFIG_ISO_PARTITION=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_STMICRO=y