Convert CONFIG_STM32_FLASH to Kconfig

This converts the CONFIG_STM32_FLASH to Kconfig by using
tools/moveconfig.py

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index b303fab..ed69ea1 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -109,6 +109,13 @@
 	 This is the driver for HyperBus controller on TI's AM65x and
 	 other SoCs
 
+config STM32_FLASH
+	bool "STM32 MCU Flash driver"
+	depends on ARCH_STM32
+	help
+	 This is the driver of embedded flash for some STMicroelectronics
+	 STM32 MCU.
+
 source "drivers/mtd/nand/Kconfig"
 
 source "drivers/mtd/spi/Kconfig"