configs: migrate CONFIG_SYS_MTDPARTS_RUNTIME to defconfigs

Move CONFIG_SYS_MTDPARTS_RUNTIME into Kconfig done by moveconfig.py.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 5e7571c..348b43e 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -22,6 +22,13 @@
 	help
 	  Enable support for parallel NOR flash.
 
+config SYS_MTDPARTS_RUNTIME
+	bool "Allow MTDPARTS to be configured at runtime"
+	depends on MTD
+	help
+	  This option allows to call the function board_mtdparts_default to
+	  dynamically build the variables mtdids and mtdparts at runtime.
+
 config FLASH_CFI_DRIVER
 	bool "Enable CFI Flash driver"
 	help