mfd: cros_ec: Instantiate properly CrOS ISH MCU device

Integrated Sensor Hub (ISH) is also a MCU running EC
having feature bit EC_FEATURE_ISH. Instantiate it as
a special CrOS EC device with device name 'cros_ish'.

Signed-off-by: Rushikesh S Kadam <rushikesh.s.kadam@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

include/linux/mfd/cros_ec.h

@@ -24,6 +24,7 @@
 
 #define CROS_EC_DEV_NAME "cros_ec"
 #define CROS_EC_DEV_PD_NAME "cros_pd"
+#define CROS_EC_DEV_ISH_NAME "cros_ish"
 
 /*
  * The EC is unresponsive for a time after a reboot command.  Add a

include/linux/mfd/cros_ec_commands.h

@@ -856,6 +856,8 @@ enum ec_feature_code {
 	EC_FEATURE_RTC = 27,
 	/* EC supports CEC commands */
 	EC_FEATURE_CEC = 35,
+	/* The MCU is an Integrated Sensor Hub */
+	EC_FEATURE_ISH = 40,
 };
 
 #define EC_FEATURE_MASK_0(event_code) (1UL << (event_code % 32))