hwmon: Add xgene hwmon driver

This patch adds hardware temperature and power reading support for
APM X-Gene SoC using the mailbox communication interface.

Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/Kconfig

@@ -1823,6 +1823,13 @@ config SENSORS_ULTRA45
 	  This driver provides support for the Ultra45 workstation environmental
 	  sensors.
 
+config SENSORS_XGENE
+	tristate "APM X-Gene SoC hardware monitoring driver"
+	depends on XGENE_SLIMPRO_MBOX || PCC
+	help
+	  If you say yes here you get support for the temperature
+	  and power sensors for APM X-Gene SoC.
+
 if ACPI
 
 comment "ACPI drivers"