Add SubHal header for Sensors HAL 2.1

Bug: 149758467
Test: compile
Change-Id: Id10d20e5d24571572565ac5d968f265ef7d7070f
diff --git a/sensors/2.0/multihal/Android.bp b/sensors/2.0/multihal/Android.bp
index 7213b44..3ce3390 100644
--- a/sensors/2.0/multihal/Android.bp
+++ b/sensors/2.0/multihal/Android.bp
@@ -28,6 +28,7 @@
     shared_libs: [
         "android.hardware.sensors@2.0",
         "android.hardware.sensors@2.0-ScopedWakelock",
+        "android.hardware.sensors@2.1",
         "libbase",
         "libcutils",
         "libfmq",