sensorhal: Enable USB mag bias

Bug: 28098931
Change-Id: I59f0bb5ed7214d8cfa29cdb845a8243d39372a74
diff --git a/device.mk b/device.mk
index 3ad439c..91da74f 100644
--- a/device.mk
+++ b/device.mk
@@ -216,6 +216,7 @@
 # Sensor & activity_recognition HAL
 TARGET_USES_NANOHUB_SENSORHAL := true
 NANOHUB_SENSORHAL_LID_STATE_ENABLED := true
+NANOHUB_SENSORHAL_USB_MAG_BIAS_ENABLED := true
 NANOHUB_SENSORHAL_SENSORLIST := $(LOCAL_PATH)/sensorhal/sensorlist.cpp
 
 PRODUCT_PACKAGES += \