mfd: ahc1ec0: Add support for Advantech embedded controller

AHC1EC0 is the embedded controller driver for Advantech industrial
products. This provides sub-devices such as hwmon and watchdog, and also
expose functions for sud-devices to read/write the value to embedded
controller.

Signed-off-by: Shihlun Lin <shihlun.lin@advantech.com.tw>

drivers/mfd/Kconfig

@@ -2118,5 +2118,14 @@ config SGI_MFD_IOC3
 	  If you have an SGI Origin, Octane, or a PCI IOC3 card,
 	  then say Y. Otherwise say N.
 
+config MFD_AHC1EC0
+	tristate "Advantech Embedded Controller Module"
+	select MFD_CORE
+	help
+          This is the core function that for Advantech EC drivers. It
+          includes the sub-devices such as hwmon, watchdog, etc. And also
+          provides expose functions for sub-devices to read/write the value
+          to embedded controller.
+
 endmenu
 endif

drivers/mfd/Makefile

@@ -264,3 +264,5 @@ obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
 
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
+
+obj-$(CONFIG_MFD_AHC1EC0) 	+= ahc1ec0.o