[DRIVER] Add driver for stm32 embedded controller

The driver has been imported from branch seco_lf-6.6.23-2.0.0_e39-dev

drivers/staging/Kconfig

@@ -78,4 +78,6 @@ source "drivers/staging/qlge/Kconfig"
 
 source "drivers/staging/vme_user/Kconfig"
 
+source "drivers/staging/mfd/Kconfig"
+
 endif # STAGING

drivers/staging/Makefile

@@ -28,3 +28,4 @@ obj-$(CONFIG_PI433)		+= pi433/
 obj-$(CONFIG_XIL_AXIS_FIFO)	+= axis-fifo/
 obj-$(CONFIG_FIELDBUS_DEV)     += fieldbus/
 obj-$(CONFIG_QLGE)		+= qlge/
+obj-$(CONFIG_MFD_SECO_STM32)	+= mfd/

drivers/staging/mfd/Kconfig

+config MFD_SECO_STM32
+	bool "SECO STM32 driver"
+	depends on I2C && PWM && GPIOLIB && SYSFS
+	select GPIOLIB_IRQCHIP
+	help
+		Support for STM32-based GPIO- and PWM-controller by SECO North.
+		Also reboots/halts the system.
+
+		Say Y if you dare.
+

drivers/staging/mfd/Makefile

+obj-$(CONFIG_MFD_SECO_STM32) += seco-stm32.o