meta-romulus: Add w83773g sensor config

Romulus uses w83773g hwmon sensor and it has 3 temperature sensors.
Add the kernel config and hwmon config to use the sensor.

Change-Id: If9ddc5eba17fa7e60b714d158c00e43d7e5378f8
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/meta-romulus/recipes-kernel/linux/linux-obmc/romulus.cfg b/meta-romulus/recipes-kernel/linux/linux-obmc/romulus.cfg
index 2a20c7e..9bdc179 100644
--- a/meta-romulus/recipes-kernel/linux/linux-obmc/romulus.cfg
+++ b/meta-romulus/recipes-kernel/linux/linux-obmc/romulus.cfg
@@ -2,3 +2,4 @@
 CONFIG_SENSORS_TMP421=y
 CONFIG_SENSORS_MAX31785=y
 CONFIG_RTC_DRV_RV8803=y
+CONFIG_SENSORS_W83773G=y